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Abstract:

The broadcast-signal transmitter according to one embodiment of the
present invention includes: an encoder for encoding physical layer pipe
(PLP) data, including a base layer and an enhancement layer of a
broadcasting service, and signaling information through a SISO, and/or
MIMO technique; a frame builder for generating a transmission frame,
which includes a preamble having the encoded signaling information and
the PLP data and an OFDM generator for modulating and transmitting a
broadcast signal including the transmission frame.

Claims:

1-4. (canceled)

5. A method for transmitting broadcast signals, the method comprising:
encoding data in each of a plurality of Physical Layer Pipes (PLPs) for
Forward Error Correction (FEC), wherein each of the plurality of PLPs
carries at least one service; mapping two signals of the encoded data
onto constellations; cell-interleaving the mapped data; time-interleaving
the cell-interleaved data; building frames including the time-interleaved
data, wherein each of the built frames include preamble having signaling
information for signaling data in the each of the built frames; and
Orthogonal Frequency Division Multiplexing (OFDM) modulating data in the
built frames and transmitting the broadcast signals including the
modulated data.

7. The method of claim 5, wherein the preamble includes a P1 symbol and
an additional P1 symbol.

8. The method of claim 5, wherein the mapped two signals are mapped into
the each of the built frame by a pair of consecutive cells.

9. The method of claim 5, wherein the method further comprises:
frequency-interleaving the data in the built frames by the pair of
consecutive cells.

10. An apparatus for transmitting broadcast signals, the apparatus
comprising: means for encoding data in each of a plurality of Physical
Layer Pipes (PLPs) for Forward Error Correction (FEC), wherein each of
the plurality of PLPs carries at least one service; means for mapping two
signals of the encoded data onto constellations; means for
cell-interleaving the mapped data; means for time-interleaving the
cell-interleaved data; means for building frames including the
time-interleaved data, wherein each of the built frames include preamble
having signaling information for signaling data in the each of the built
frames; and means for Orthogonal Frequency Division Multiplexing (OFDM)
modulating data in the built frames and transmitting the broadcast
signals including the modulated data.

12. The apparatus of claim 10, wherein the preamble includes a P1 symbol
and an additional P1 symbol.

13. The apparatus of claim 10, wherein the mapped two signals are mapped
into the each of the built frames by a pair of consecutive cells.

14. The apparatus of claim 10, wherein the apparatus further comprises:
means for frequency-interleaving the data in the built frames by the pair
of consecutive cells.

15. A method for receiving broadcast signals, the method comprising:
receiving the broadcast signals and Orthogonal Frequency Division
Multiplexing (OFDM) demodulating the received broadcast signal; parsing
frames from the demodulated broadcast signal, wherein each of the frames
includes a plurality of Physical Layer Pipes (PLPs) and a preamble having
signaling information for signaling the plurality of PLPs, wherein each
of the plurality of PLPs carries at least one service;
time-deinterleaving data in the parsed frames; cell-deinterleaving the
time-deinterleaved data; demapping the cell-deinterleaved data; and
decoding the demapped data for Forward Error Correction (FEC).

17. The method of claim 15, wherein the preamble includes a P1 symbol and
an additional P1 symbol.

18. The method of claim 15, wherein two signals of the demapped data are
consecutive cells mapped into the each of the frames by a pair of
consecutive cells.

19. The method of claim 15, wherein the method further comprises:
frequency-deinterleaving the data in the built frames by the pair of
consecutive cells.

20. An apparatus for receiving broadcast signals, the apparatus
comprising: means for receiving the broadcast signals and Orthogonal
Frequency Division Multiplexing (OFDM) demodulating the received
broadcast signal; means for parsing frames from the demodulated broadcast
signal, wherein each of the frames includes a plurality of Physical Layer
Pipes (PLPs) and a preamble having signaling information for signaling
the plurality of PLPs, wherein each of the plurality of PLPs carries at
least one service; means for time-deinterleaving data in the parsed
frames; means for cell-deinterleaving the time-deinterleaved data; means
for demapping the cell-deinterleaved data; and means for decoding the
demapped data for Forward Error Correction (FEC).

22. The apparatus of claim 20, wherein the preamble includes a P1 symbol
and an additional P1 symbol.

23. The apparatus of claim 20, wherein two signals of the demapped data
are consecutive cells mapped into the each of the frames by a pair of
consecutive cells.

24. The apparatus of claim 20, wherein the apparatus further comprises:
means for frequency-deinterleaving the data in the built frames by the
pair of consecutive cells.

Description:

FIELD OF THE INVENTION

[0001] The present invention relates to a method for transceiving
broadcast signals and an apparatus for transceiving broadcast signals,
and more particularly, to a method for transceiving broadcast signals,
which can enhance data transmission efficiency and is compatible with
conventional methods for transceiving broadcast signals, and a
transceiving apparatus thereof.

BACKGROUND ART

[0002] A broadband wireless communication system is based on an orthogonal
frequency division multiplexing (OFDM) scheme and an orthogonal frequency
division multiple access (OFDMA) scheme, and transmits a physical channel
signal using a plurality of subcarriers so as to implement high-speed
data transmission.

[0003] Downlink data types transmitted from a base station (BS) to a
mobile station (MS) can be largely classified into a
multicasting/broadcasting data type and a unicast type. The
multicasting/broadcasting data type can be used for the BS to transmit
system information, configuration information, software update
information, etc. to one or more groups including unspecific/specific
MSs. The unicast data type may be used for the BS to transmit requested
information to a specific MS, or may also be used to transmit a message
including information (for example, configuration information) to be
transferred only to a specific MS.

DETAILED DESCRIPTION OF THE INVENTION

Technical Problem

[0004] A technical object of one embodiment of the present invention is to
provide a method and apparatus for transceiving broadcast signals, which
can enhance data transmission efficiency in a digital broadcast system.

[0005] A further technical object of the present invention is to provide a
method and apparatus for transceiving broadcast signals, which can
maintain compatibility with a conventional broadcast system in addition
to achieving the above described objects.

Technical Solution

[0006] The object of the present invention can be achieved by providing a
method for receiving a broadcast signal including: receiving a broadcast
signal including a transmission frame configured to transmit a broadcast
service, and OFDM-demodulating the received broadcast signal; parsing the
transmission frame contained in the OFDM-demodulated broadcast signal,
wherein the transmission frame includes a preamble and PLP
(Physical_Layer_Pipe) data, the preamble includes signaling information,
the signaling information configured to transmit decoding information of
the PLP data, and the PLP data configured to include a base layer and an
enhancement layer of a broadcast service; and decoding the signaling
information and the PLP data using at least one of SISO, MISO and MIMO.

Effects of the Invention

[0007] As is apparent from the above description, in a digital broadcast
system, it is possible to enhance data transmission efficiency and
increase robustness in terms of transmission and reception of broadcast
signals, by virtue of provision of a MIMO system.

[0008] Further, according to the present invention, in a digital broadcast
system, it is possible to decode MIMO receiving signals efficiently using
MIMO processing of the present invention even under a diverse broadcast
environment.

[0009] In addition, according to the present invention, a broadcast system
using MIMO of the present invention can achieve the above described
advantages while maintaining compatibility with a conventional broadcast
system not using MIMO.

[0010] Further, according to the present invention, it is possible to
provide a method and apparatus for transceiving broadcast signals, which
can receive digital broadcast signals without error even under an indoor
environment or using mobile reception equipment.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] FIG. 1 shows a broadcast signal transmitter using MIMO according to
an embodiment of the present invention.

[0012]FIG. 2 shows a broadcast signal receiver according to an embodiment
of the present invention.

[0013] FIG. 3 shows an additional frame structure based on PLP according
to an embodiment of the present invention.

[0014]FIG. 4 shows an additional frame structure based on FEF according
to an embodiment of the present invention.

[0015] FIGS. 5 A and B show a process of generating a P1 symbol in order
to perceive an additional frame according to an embodiment of the present
invention.

[0016] FIG. 6 shows a conceptual diagram of a broadcast signal
transmitting method according to an embodiment of the present invention.

[0017] FIG. 7 shows a conceptual diagram of a broadcast signal
transmitting method according to another embodiment of the present
invention.

[0018] FIG. 8 shows a broadcast signal transmitted by a national broadcast
system with a MIMO system applied using SVC.

[0019]FIG. 9 shows a MIMO transmitting/receiving system according to an
embodiment of the present system.

[0020]FIG. 10 shows a structure of a P1 symbol and AP1 symbol according
to an embodiment of the present invention.

[0021]FIG. 11 shows a P1 symbol detection module according to an
embodiment of the present invention.

[0022]FIG. 12 shows an AP1 symbol detection module according to an
embodiment of the present invention.

[0023] FIG. 13 shows an input processor of a broadcast signal transmitter
according to an embodiment of the present invention.

[0024]FIG. 14 shows a mode adaption module implementing a plurality of
PLP as an input processor according to an embodiment of the present
invention.

[0025]FIG. 15 shows a stream adaption module implementing a plurality of
PLP as an input processor according to an embodiment of the present
invention.

[0026] FIG. 16 shows a BICM encoder according to an embodiment of the
present invention.

[0027]FIG. 17 shows a BICM encoder according to another embodiment of the
present invention.

[0028] FIG. 18 shows a frame builder encoder according to an embodiment of
the present invention.

[0029] FIG. 19 shows an OFDM generator according to an embodiment of the
present invention.

[0030] FIG. 20 shows an OFDM demodulator according to an embodiment of the
present invention.

[0031]FIG. 21 shows a frame demapper according to an embodiment of the
present invention.

[0032] FIG. 22 shows a BICM decoder according to an embodiment of the
present invention.

[0033] FIG. 23 shows a BICM decoder according to another embodiment of the
present invention.

[0034]FIG. 24 shows an output processor according to an embodiment of the
present invention.

[0035]FIG. 25 shows an output processor according to another embodiment
of the present invention.

[0036] FIG. 26 shows a frame structure according to an embodiment of the
present invention.

[0037] FIG. 27 shows another frame structure according to another
embodiment of the present invention.

[0038] FIG. 28 shows a superframe structure according to an embodiment of
the present invention.

[0039]FIG. 29 is a flowchart illustrating a method for transmitting a
broadcast signal according to an embodiment of the present invention.

[0040]FIG. 30 is a flowchart illustrating a method for receiving a
broadcast signal according to an embodiment of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

[0041] Hereinafter, although the preferred embodiments of the present
invention will be described in detail with reference to the accompanying
drawings and contents as described with relation to the accompanying
drawings, it is to be understood that the present invention is not
limited to the embodiments.

[0042] Various technologies have been introduced to increase transmission
efficiency and to perform robust communication in a digital broadcast
system. One of such technologies is a method of using a plurality of
antennas at a transmitting side or a receiving side. This method may be
classified into a Single-Input Single-Output (SISO) scheme in which
transmission is performed through a single antenna and reception is
performed through a single antenna, a Single-Input Multi-Output (SIMO)
scheme in which transmission is performed through a single antenna and
reception is performed through multiple antennas, a Multi-Input
Single-Output (MISO) scheme in which transmission is performed through
multiple antennas and reception is performed through a single antenna,
and a Multi-Input Multi-Output (MIMO) scheme in which transmission is
performed through multiple antennas and reception is performed through
multiple antennas. Although the multiple antennas may be exemplified by 2
antennas for ease of explanation in the following description, the
description of the present invention may be applied to systems that use 2
or more antennas.

[0043] The SISO scheme corresponds to a general broadcast system that uses
1 transmission antenna and 1 reception antenna. The SIMO scheme
corresponds to a broadcast system that uses 1 transmission antenna and a
plurality of reception antennas.

[0044] The MISO scheme corresponds to a broadcast system that uses a
plurality of transmission antennas and 1 reception antenna to provide
transmit diversity. An example of the MISO scheme is an Alamouti scheme.
In the MISO scheme, it is possible to receive data through 1 antenna
without performance loss. Although a reception system can receive the
same data through a plurality of reception antennas in order to improve
performance, this case will be described as belonging to MISO cases in
this specification.

[0045] A MIMO scheme corresponds to a broadcast system that uses a
plurality of transmit (Tx) antennas and a plurality of receive (Rx)
antennas to provide transmission/reception (Tx/Rx) diversity and high
transmission efficiency. In the MIMO scheme, signals are processed in
different ways in time and space dimensions and a plurality of data
streams is transmitted through parallel paths that simultaneously operate
in the same frequency band to achieve diversity effects and high
transmission efficiency.

[0046] The performance of a system that employs the MIMO technology
depends on characteristics of a transmission channel. The efficiency of
such a system is high, especially, when the system has independent
channel environments. That is, the performance of the system that employs
the MIMO technology may improve when channels of all antennas ranging
from antennas of the transmitting side and antennas of the receiving side
are independent channels that have no correlation to each other. However,
in a channel environment in which the correlations between channels of
transmission and reception antennas are very high as in a line-of-sight
(LOS) environment, the performance of the system that employs the MIMO
technology may be significantly reduced or the system may not be able to
operate.

[0047] In addition, if the MIMO scheme is applied to a broadcast system
that uses the SISO and MISO schemes, it is possible to increase data
transmission efficiency. However, in addition to the above problems,
there is a need to maintain compatibility to allow a receiver having a
single antenna to receive services. Accordingly, the present invention
suggests a method for solving such existing problems.

[0048] In addition, the present invention can provide a broadcast signal
transmitter/receiver and a broadcast transmission and reception method
for a conventional terrestrial broadcast system and a system that can
transmit and receive additional broadcast signals (or enhanced broadcast
signals), for example, mobile broadcast signals, while sharing an RF
frequency band with a terrestrial broadcast system such as DVB-T2.

[0049] To accomplish this, in the present invention, it is possible to use
a video coding method having scalability in which a basic video component
which has low image quality although it is robust to a communication
environment and an extended video component which is slightly weak to a
communication environment although it can provide a high-quality image
can be distinguishably transmitted. Although the present invention will
be described with reference to SVC as a video coding method having
scalability, the present invention may be applied to any other video
coding methods. Embodiment of the present invention will be described in
more detail with reference to the drawings.

[0050] A broadcast signal transmitter and receiver of the present
invention can perform MISO processing and MIMO processing on a plurality
of signals that are transmitted and received through a plurality of
antennas. The following is a description of a broadcast signal
transmitter and receiver that performs signal processing on 2 signals
that are transmitted and received through 2 antennas.

[0051] FIG. 1 shows a broadcast signal transmitter using MIMO according to
an embodiment of the present invention.

[0052] As shown in FIG. 1, the broadcast signal transmitter according to
the present invention may include an input processor 101100, an input
processing module 101200, a Bit Interleaved Coded Modulation (BICM)
encoder 101300, a frame builder 101400, and an Orthogonal
Frequency-Division Multiplexing (OFDM) generator (or transmitter) 101500.
The broadcast signal transmitter according to the present invention may
receive a plurality of MPEG-TS streams or a General Stream Encapsulation
(GSE) stream (or GS stream).

[0053] The input processor 101100 may generate a plurality of PLPs
(physical layer pipes) on a service basis in order to give robustness to
a plurality of input streams, i.e., a plurality of MPEG-TS streams or GSE
streams.

[0054] PLPs are data units that are identified in the physical layer.
Specifically, a PLP is data having the same physical layer attribute
which is processed in the transmission path and may be mapped on a cell
by cell basis in a frame. In addition, a PLP may be considered a physical
layer Time Division Multiplexing (TDM) channel that carries one or a
plurality of services. Specifically, a path through which such a service
is transmitted is transmitted or a stream identifiable in the physical
layer which is transmitted through the path is referred to as a PLP.

[0055] Thereafter, the input processing module 101200 may generate a Base
Band (BB) frame including a plurality of generated PLPs. The BICM module
101300 may add redundancy to the BB frame to correct an error in a
transmission channel and may interleave PLP data included in the BB
frame.

[0056] The frame builder 101400 may accomplish a transmission frame
structure by mapping the plurality of PLPs to a transmission frame and
adding signaling information thereto. The OFDM generator 101500 may
demodulate input data from the frame builder according to OFDM to divide
the input data into a plurality of paths such that the input data is
transmitted through a plurality of antennas.

[0057]FIG. 2 shows a broadcast signal receiver according to an embodiment
of the present invention.

[0058] As shown in FIG. 2, the broadcast signal receiver may include an
OFDM demodulator 107100, a frame parser 107200, a BICM decoder 107300,
and an output processor 107400. The OFDM demodulator 107100 may convert
signals received through a plurality of receive antennas into signals in
the frequency domain. The frame parser 107200 may output PLPs for a
necessary service from among the converted signals. The BICM decoder
107300 may correct an error generated according to a transmission
channel. The output processor 107400 may perform procedures necessary to
generate output TSs or GSs. Here, dual polarity signals may be input as
input antenna signals and one or more streams may be output as the TXs or
GSs.

[0059] FIG. 3 shows an additional frame structure based on PLP according
to an embodiment of the present invention.

[0060] As shown in FIG. 3, a frame according to an embodiment of the
present invention may include a preamble area and a data area. The
preamble area may include a P1 symbol and a P2 symbol and the data area
may include a plurality of data symbols. The P1 symbol may transmit P1
signaling information and P2 symbol may transmit L1-signaling
information.

[0061] In this case, a preamble symbol may be additionally allocated to
the preamble. This additional preamble symbol is referred to as an
Additional Preamble 1 (AP1). In an embodiment of the present invention,
one or more AP1 symbols may be added to a frame in order to improve
detection performance of a mobile broadcast signal under very low SNR or
time-selective fading conditions. AP1 signaling information transmitted
through the AP1 symbol may include an additional transmission parameter.

[0062] AP1 signaling information according to an embodiment of the present
invention includes pilot pattern information in a frame. Thus, according
to an embodiment of the present invention the broadcast signal receiver
does not transmit P2 symbol, if L1 signaling information is spread in
data symbols of the data area, pilot pattern information can be
discovered by using the AP1 signaling information before L1 signaling
information in the data area is decoded.

[0063] Also, if the L1-signaling information in the data area of a frame
is spread, AP1 signaling information can include information necessary
for the broadcast signal receiver to decode signaling information spread
in a frame of the data area. According to the present invention, a
preamble area of a frame includes a P1 symbol, more than one AP1 symbols,
and more than one P2 symbols. And the data area comprises a plurality of
data symbols, also known as data OFDM symbol. A P2 symbol is optional and
whether it is inserted is determined by signaling AP1 signaling
information through AP1 symbols according to an embodiment of the present
invention.

[0064] In an embodiment of the present invention, a P1 insertion module in
the OFDM generator OFDM generator 101500 of the broadcast signal
transmitter may insert the P1 symbol and the AP1 symbol into every
symbol. That is, the P1 insertion module may insert 2 or more preamble
symbols into every frame. In another embodiment, an AP1 insertion module
may be added downstream of (or next to) the P1 insertion module and the
AP1 insertion module may insert the AP1 symbol. If 2 or more preamble
symbols are used as in the present invention, there are advantages in
that robustness to burst fading that may occur in a mobile fading
environment is further increased and signal detection performance is also
improved.

[0065] The P1 symbol may transmit P1 signaling information associated with
a basic transmission parameter and transmission type and a corresponding
preamble identifier and the receiver may detect the frame using the P1
symbol. A plurality of P2 symbols may be provided and may carry L1
signaling information and signaling information such as a command PLP.
The L1 signaling information may include L1-pre signaling information and
L1-post signaling information, the L1-pre signaling information may
include information necessary to receive and decode the L1-post signaling
information. Also, the L1-post signaling information may include
parameters necessary for the receiver to encode PLP data.

[0066] As shown in FIG. 3, the L1-post signaling information may be
located next to L1-pre signaling information.

[0067] The L1-post signaling information may include a configurable block,
a dynamic block, an extension block, a cyclic redundancy check (CRC)
block, and an L1 padding block.

[0068] The configurable block may include information equally applied to
one transmission frame and the dynamic block may include characteristic
information corresponding to a currently transmitted frame.

[0069] The extension block may be used when the L1-post signaling
information is extended, and the CRC block may include information used
for error correction of the L1-post signaling information and may have 32
bits. The padding block may be used to adjust sizes of information
respectively included in a plurality of encoding blocks to be equal when
the L1-post signaling information is transmitted while being divided into
the encoding blocks and has a variable size.

[0070] The common PLP may include network information such as a NIT
(Network Information Table) or PLP information and service information
such as an SDT (Service Description Table) or an EIT (Event Information
Table). The preamble of the present invention may include only the P1
symbol, the L1-pre signaling information, and the L1-post signaling
information or may include all of the P1 symbol, the L1-pre signaling
information, the L1-post signaling information, and the common PLP
according to designer intention. A plurality of data symbols located next
to the P1 symbol may include a plurality of PLPs. The plurality of PLPs
may include audio, video, and data TS streams and PSI/SI information such
as a Program Association Table (PAT) and a Program Map Table (PMT). In
the present invention, a PLP that transmits PSI/SI information may be
referred to as a base PLP or a signaling PLP. The PLPs may include a
type-1 PLP that is transmitted through one sub-slice per frame and a
type-2 PLP that is transmitted through two sub-slices per frame. The
plurality of PLPs may transmit one service and may also transmit service
components included in one service. When the PLPs transmit service
components, the transmitting side may transmit signaling information
which indicates that the PLPs transmit service components. In addition,
additional data (or an enhanced broadcast signal) in addition to basic
data may be transmitted through a specific PLP while sharing an RF
frequency band with the conventional terrestrial broadcast system
according to an embodiment of the present invention. In this case, the
transmitting side may define a system or a signal that is currently
transmitted through signaling information of the P1 symbol described
above. The following description is given with reference to the case in
which the additional data is video data. That is, as shown in FIG. 3, PLP
M1 112100 and PLP (M1+M2) 112200 which are type 2 PLPs may be transmitted
while including additional video data. In addition, in the present
invention, a frame that transmits such additional video data may be
referred to as an additional frame and a frame that transmits basic data
may be referred to as a basic frame (or T2 frame).

[0071] In addition, a frame that can transmit not only additional data but
also data associated with a new broadcast system different from the
conventional terrestrial broadcast system may be referred to as an
additional frame. In this case, a frame that transmits a conventional
terrestrial broadcast may be referred to as a terrestrial broadcast frame
and an additional frame may transmit additional data or basic data
associated with the new broadcast system.

[0072]FIG. 4 illustrates a structure of an additional frame based on FEF
according to an embodiment of the present invention.

[0073] Specifically, FIG. 4 shows the case in which a Future Extension
Frame (FEF) is used in order to transmit additional video data. In the
present invention, a frame that transmits basic video data may be
referred to as a basic frame and an FEF that transmits additional video
data may be referred to as an additional frame.

[0074]FIG. 4 shows structures of superframes 11100 and 113200 in each of
which a basic frame and an additional frame are multiplexed. Frames
113100-1 to 113100-n that are not shaded from among frames included in
the superframe 113100 are basic frames and shaded frames 113120-1 and
113120-2 are additional frames.

[0075]FIG. 4(A) shows the case in which the ratio of basic frames to
additional frames is N:1. In this case, the time required for the
receiver to receive a next additional frame 113120-2 after receiving one
additional frame 113120-1 may correspond to N basic frames.

[0076]FIG. 4(B) shows the case in which the ratio of basic frames to
additional frames is 1:1. In this case, the proportion of additional
frames in the superframe 113200 may be maximized and therefore the
additional frames may have a structure very similar to that of the basic
frames in order to maximize the extent of sharing with the basic frames.
In addition, in this case, the time required for the receiver to receive
a next additional frame 113210-2 after receiving one additional frame
113210-1 corresponds to 1 basic frame 113220 and therefore the superframe
period is shorter than that of FIG. 4(A).

[0077] FIGS. 5(A) and 5(B) illustrate a P1 symbol generation procedure for
identifying additional frames according to an embodiment of the present
invention.

[0078] In the case in which additional video data is transmitted through
additional frames which are distinguished from basic frames as shown in
FIG. 4, there is a need to transmit additional signaling information for
enabling the receiver to identify and process an additional frame. An
additional frame of the present invention may include a P1 symbol for
transmitting such additional signaling information and the P1 symbol may
be referred to as a new_system_P1 symbol. This new_system_P1 symbol may
be different from a P1 symbol that is used in a conventional frame and a
plurality of new_system_P1 symbols may be provided. In an embodiment, the
new_system_P1 symbol may be located before a first P2 symbol in a
preamble area of the frame.

[0079] In the present invention, a P1 symbol of a conventional frame may
be modified and used to generate the minimum Hamming distance. The
present invention suggests a method in which a minimum Hamming distance
is generated by modifying the structure of the P1 symbol of the
conventional frame or is generated by changing the symbol generator
114100 that generates symbols.

[0080] FIG. 5(A) shows the structure of the P1 symbol of the conventional
frame. In the present invention, the structure of the P1 symbol of the
conventional frame shown in FIG. 5(A) may be modified to generate a
minimum Hamming distance. In this case, the minimum Hamming distance may
be generated by changing a frequency displacement f_SH for the prefix and
postfix of the conventional P1 symbol or changing the length
(specifically, the size of T_P1C or T_P1B) of the P1 symbol. However, in
the case in which the minimum Hamming distance is generated by modifying
the structure of the P1 symbol, there is a need to appropriately modify
parameters (the sizes of T_P1C and T_P1B and f_SH) used in the P1 symbol
structure.

[0081] FIG. 5(B) shows the P1 symbol generator that generates P1 symbols.
In the present invention, the P1 symbol generator shown in FIG. 5(B) may
be modified to generate a minimum Hamming distance. In this case, a
minimum Hamming distance may be generated using a method which changes
the distribution of active carriers used for a P1 symbol in a CDS table
module 114110, an MSS module 114120, and a C-A-B structure module 114130
included in the P1 symbol generator (for example, a method in which the
CDS table module 114110 uses a different Complementary Set of Sequence
(CSS)) or a method which changes a pattern for information that is
transmitted through a P1 symbol (for example, a method in which the MSS
module 114120 uses a different Complementary Set of Sequence (CSS)).

[0082] In addition, the AP1 symbol of the present invention described
above with reference to FIG. 3 may be generated through the procedure
described above with reference to FIG. 5.

[0083] In addition, the present invention proposes a MIMO system using
scalable video coding (SVC). SVC is a video coding method developed to
cope with a variety of terminals and communication environments and
variations in the terminals and communication environments. SVC can code
a video hierarchically such that desired definition is generated and
transmit additional video data having a base layer from which video data
about an image having basic definition can be restored and an enhancement
layer from which an image having higher definition can be restored.
Accordingly, a receiver can acquire the basic definition image by
receiving and decoding only the video data of the base layer, or obtain
the higher definition image by decoding the video data of the base layer
and the video data of the enhancement layer according to characteristics
thereof. In the following description, the base layer can include video
data corresponding to the base layer and the enhancement layer can
include video data corresponding to the enhancement layer. In the
following, video data may not be a target of SVC, the base layer can
include data capable of providing a fundamental service including basic
video/audio/data corresponding to the base layer, and the enhancement
layer can include data capable of providing a higher service including
higher video/audio/data corresponding to the enhancement layer.

[0084] The present invention proposes a method of transmitting the base
layer of SVC through a path through which signals can be received
according to SISO or MISO using SVC and transmitting the enhancement
layer of SVC through a path through which signals can be received
according to MIMO in the broadcast system of the present invention. That
is, the present invention provides a method by which a receiver having a
single antenna acquires an image with basic definition by receiving the
base layer using SISO or MISO and a receiver having a plurality of
antennas acquires an image with higher definition by receiving the base
layer and the enhancement layer using MIMO.

[0085] A description will be given of a method of transmitting the MIMO
broadcast data including the base layer and the enhancement layer in
association with terrestrial broadcast frames for transmitting
terrestrial broadcast signals.

[0087] It is possible to transmit the MIMO broadcast data included in a
predetermined PLP while distinguishing the predetermined PLP from a PLP
including terrestrial broadcast data. In this case, the predetermined PLP
is used to transmit the MIMO broadcast data, and signaling information
for describing the predetermined PLP may be additionally transmitted to
prevent an error in the conventional receiving system. In the following,
the predetermined PLP including the MIMO broadcast data may be referred
to as a MIMO broadcast PLP and the PLP including the terrestrial
broadcast data may be referred to as a terrestrial broadcast PLP.

[0088] As MIMO broadcast data may not be implemented in a terrestrial
broadcast receiver, it is necessary to have additional information for
signalling to distinguish terrestrial PLP and MIMO broadcast PLP. In this
case, signaling can use a reserved field in the L1 signaling information
of the terrestrial broadcast system. When a plurality of anttenas are
used for transmitting MIMO broadcast data on the transmitting side, the
terrestrial broadcast data can be transmitted by MISO. The present
invention, in order to perceive PLP, utilizes L1-post signaling
information.

[0090] It is possible to include the MIMO broadcast data generated as
described above in a predetermined frame and to transmit the
predetermined frame including the MIMO broadcast data while
distinguishing the predetermined frame from a terrestrial broadcast
frame. In this case, the predetermined frame is used to transmit the MIMO
broadcast data, and signaling information for describing the
predetermined frame may be additionally transmitted to prevent an error
in the conventional receiving system.

[0092] PLPs including MIMO broadcast data may be transmitted through a
terrestrial broadcast frame and a MIMO broadcast frame. Since a MIMO
broadcast PLP may be present in the terrestrial broadcast frame (or basic
frame), distinguished from the above-mentioned embodiments, it is
necessary to signal the relationship between connected PLPs present in
the terrestrial broadcast frame and the MIMO broadcast frame. To achieve
this, the MIMO broadcast frame may also include L1 signaling information,
and information about the MIMO broadcast PLP present in the broadcast
frame may be transmitted along with L1 signaling information of the
terrestrial broadcast frame.

[0093] MIMO broadcast PLP data in different frames are connected by using
PLP fields including L1-post signanling information. According to an
embodiment of the present invention, the receiving system includes as
L1-post signaling information PLP_ID information, PLP+TYPE information,
PLP_PAYLOAD_TYPE information, PLP_GROYP_ID information, uses those
information to check the PLP connection between MIMO broadcast PLP data.
It then acquires services by continuously decoding desired MIMO broadcast
PLP data.

[0094] The terrestrial broadcast PLP in the terrestrial broadcast frames
can be transmitted as a preset mode and also as mentioned a new mode to
support the MIMO system can be transmitted. According to an embodiment of
the present invention, the MIMO broadcast PLP in the terrestrial
broadcast frames as a base layer can be transmitted by MISO or SISO
method and MIMO broadcast PLP in MIMO broadcast frames as an enhancement
layer can be transmitted by the MIMO method.

[0096] As shown in FIG. 6, terrestrial broadcast data and MIMO broadcast
data in frame units can be distinctively transmitted. The FEF length of a
MIMO broadcast frame (FEF) can be allocated in between terrestrial
broadcast frames in an FEF interval. In this case, MIMO system data can
co-exist in a frequency band within the terrestrial broadcast system, and
malfunction can be prevented by the broadcast signal receiver perceiving
a frame through L1 signaling and ignoring MIMO broadcast frames. In that
case, the MIMO system can use some of the thruput by FEF related
parameters such as FEF_TYPR, FEF_LENGTH, FEF_INTERVAL defined by the
L1-post signaling information.

[0097] FIG. 7 shows a conceptual diagram for a broadcast signal
transmitting method according to another embodiment of the present
invention.

[0098] FIG. 7 indicates, as shown in the method 3, transmitting the
broadcast signals of the MIMO broadcast system in terrestrial broadcast
system. The MIMO broadcast services (MIMO broadcast service 1˜n)
encodes each SVC encoder (18010, 18020) through a base layer and
enhancement layer. Scheduler&BICM (Bit Interleaved Coding and Modulation)
module (18030) allocates the base layers of the MIMO broadcast services
with the terrestrial broadcast frames and the enhancement layers with
MIMO encoders (18040, 18050). The enhancement layers encodes by each MIMO
encoder (18040, 18050) and transmits to the MIMO broadcast frame of the
MIMO broadcast system. The base layers are transmitted in the terrestrial
broadcast frames and in that case, SISO or MISO supported by the
terrestrial broadcast system.

[0099] When broadcast signals including the terrestrial broadcast frames
and the MIMO broadcast frames, as mentioned in the method 1 and 3,
singaling information is created and the terrestrial broadcast receiver
perceives terrestrial broadcast PLP in the terrestrial broadcast frames.
Thus, the receiver can acquire the terrestrial broadcast services without
malfunctioning. Also, the MIMO broadcast receiver can acuire and provide
the MIMO broadcast service corresponding to the base layer only by the
terrestrial broadcast frame. It can acquire and provide the MIMO
broadcast service corresponding to the base layer and enhancement layer
by acquiring the MIMO broadcast PLP of the terrestrial broadcast frame
and MIMO broadcast frame of the MIMO broadcast frame.

[0100] The MIMO broadcast PLP in the terrestrial broadcast frame can only
be transmitted by MISO/MIMO. In that case, the MIMO broadcast PLP, as the
system demands, can include a code rate of new error correction codes
(such as 1/4, 1/3, 1/2), and new time interleaving mode and can only
transmit to a base layer.

[0101] The MIMO broadcast PLP of the MIMO broadcast frame includes PLP of
the SISO, MISO, and MIMO methods. In that case, PLP of the SISO/MISO
methods or a base layer in a carrier can be transmitted and PLP of the
MIMO method or the carrier can transmit the enhancement layer. The rate
of PLP of the SISO/MISO methods, or carrier and PLP of the MIMO method,
or carrier can be varied from 0 to 100%. The ract can be determined for
each frame accordingly.

[0102] FIG. 8 shows broadcast signals transmitted by a broadcast system
being applied by a MIMO system using a SVC.

[0103] FIG. 8 shows a broadcast signal that allocates terrestrial data and
MIMO broadcast data to a frame or PLP by using the SVC and generating a
base and enhancement layer.

[0104] FIG. 8 A shows a broadcast signal transmitted by a broadcast system
being applied by a MIMO transmitting system by using the SVC.

[0105] The broadcast system in FIG. 8 A transmits broadcast signals
including a terrestrial broadcast frame and MIMO broadcast frame. The
MIMO broadcast PLP in FIG. 8 A can exist in a terrestrial broadcast frame
or a MIMO broadcast frame. The MIMO broadcast PLP in the terrestrial
broadcast frame as a base layer can be transmited by the SISO or MISO
method and the MIMO braod cast PLP in the MIMO broadcast frame as an
enhancement layer can be transmitted by the SISO, MISO, or MIMO method.

[0106] FIG. 8 B shows a broadcast signal being applied by a MIMO
transmitting system using a SVC.

[0107] In FIG. 8 B, the broadcast system transmits broadcast signals
including the terrestrial broadcast frame and the MIMO broadcast frame.
The MIMO broadcast PLP in FIG. 8 B only exists in the MIMO broadcast
frame. In that case, the MIMO broadcast PLP indludes PLP with a base
layer and PLP with an enhancement layer. The PLP with the base layer can
be transmitted by the SISO or MISO method, and the PLP with the
enhancement layer can be transmitted by the SISO, MISO, or MIMO method.
The rate of the PLP with base layer and the PLP with enhancement layer
can be varied from 0 to 100%.

[0108] FIG. 8 C shows a broadcast signal transmitted by a broadcast system
being applied by a MIMO transmitting system using a SVC.

[0109] The broadcast system of FIG. 8 C transmits broadcast signals
including terrestrial broadcast frames and MIMO broadcast frames. The
MIMO broadcast data exists only in the MIMO broadcast frame. But, as
opposed to FIG. 8 B, a base layer and an enhancement layer are not
transmitted by PLP but carriers.

[0110] Various technologies are introduced to improve transmission
efficiency and perform robust communication in a digital broadcast
system. One of the technologies is a method of using a plurality of
antennas at a transmitting side or a receiving side. This method may be
divided into SISO (Single-Input Single-Output), SIMO (Single-Input
Multi-Output), MISO (Multi-Input Sinle-Output) and MIMO (Multi-Input
Multi-Output). While multiple antennas are described as two antennas in
the following, the present invention is applicable to systems using two
or more antennas.

[0111] In an embodiment, MIMO can use spatial multiplexing (SM) and Golden
code (GC) schemes, which will be described in detail.

[0112] A modulation scheme in broadcast signal transmission may be
represented as M-QAM (Quadrature Amplitude Modulation) in the following
description. That is, BPSK (Binary Phase Shift Keying) can be represented
by 2-QAM when M is 2 and QPSK (Quadrature Phase Shift Keying) can be
represented by 4-QAM when M is 4. M can indicate the number of symbols
used for modulation.

[0113] A description will be given of a case in which a MIMO system
transmits two broadcast signals using two transmit antennas and receives
two broadcast signals using two receive antennas as an example.

[0114]FIG. 9 illustrates MIMO transmission and reception systems
according to an embodiment of the present invention.

[0115] As shown in FIG. 9, the MIMO transmission system includes an input
signal generator 201010, a MIMO encoder 201020, a first transmit antenna
201030, and a second transmit antenna 201040. In the following, the input
signal generator 201010 may be referred to as a divider and the MIMO
encoder 201020 may be referred to as a MIMO processor.

[0116] Although not shown in the drawings, the MIMO reception system may
include a first receive (Rx) antenna, a second receive (Rx) antenna, a
MIMO decoder, and an output signal generator. In the following
description, the output signal generator may also be referred to as a
merger and the MIMO decoder may also be referred to as an ML detector.

[0117] In the MIMO transmission system, the input signal generator 201010
generates a plurality of input signals for transmission through a
plurality of antennas. In the following, the input signal generator
201010 may be referred to as a divider. Specifically, the input signal
generator 201010 may divide an input signal for transmission into 2 input
signals and output the first input signal S1 and the second input signal
S2 for MIMO transmission.

[0118] The MIMO encoder 201020 may perform MIMO encoding on the plurality
of input signals S1 and S2 and output a first transmission signal St1 and
a second transmission signal St2 for MIMO transmission and the output
transmission signals may be transmitted through a first antenna 201030
and a second antenna 201040 via required signal processing and modulation
procedures. The MIMO encoding 201020 may perform encoding on a per symbol
basis. The SM scheme or the GC scheme may be used as the MIMO encoding
method. In the following, the MIMO encoder may be referred to as a MIMO
processor. Specifically, the MIMO encoder may process a plurality of
input signals according to a MIMO matrix and a parameter value of the
MIMO matrix which are described below.

[0119] The input signal generator 201010 is an element that outputs a
plurality of input signals for MIMO encoding and may also be an element
such as a demultiplexer or a frame builder depending on the transmission
system. The input signal generator 201010 may also be included in the
MIMO encoder 201020 such that the MIMO encoder 201020 generates a
plurality of input signals and performs encoding on the plurality of
input signals. The MIMO encoder 201020 may be a device that performs MIMO
encoding or MIMO processing on a plurality of signals and outputs the
encoded or processed signals so as to acquire diversity gain and
multiplexing gain of the transmission system.

[0120] Since signal processing should be performed on a plurality of input
signals after the input signal generator 201010, a plurality of devices
may be provided next to the input signal generator 201010 to process
signals in parallel or one device including one memory may be provided to
sequentially process signals or to simultaneously process signals in
parallel.

[0121] The MIMO reception system receives a first reception signal Sr1 and
a second reception signal Sr2 using a first receive antenna and a second
receive antenna. The MIMO decoder 201070 then processes the first
reception signal and the second reception signal and outputs a first
output signal and a second output signal. The MIMO decoder 201070
processes the first reception signal and the second reception signal
according to the MIMO encoding method used by the MIMO encoder 201020. As
an ML detector, the MIMO decoder 201070 outputs a first output signal and
a second output signal using information regarding the channel
environment, reception signals, and the MIMO matrix used by the MIMO
encoder in the transmission system. In an embodiment, when ML detection
is performed, the first output signal and the second output signal may
include probability information of bits rather than bit values and may
also be converted into bit values through FEC decoding.

[0122] The MIMO decoder of the MIMO reception system processes the first
reception signal and the second reception signal according to the QAM
type of the first input signal and the second input signal processed in
the MIMO transmission system. Since the first reception signal and the
second reception signal received by the MIMO reception system are signals
that have been transmitted after being generated by performing MIMO
encoding on the first input signal and the second input signal of the
same QAM type or different QAM types, the MIMO reception system may
determine a combination of QAM types of the reception signals to perform
MIMO decoding on the reception signals. Accordingly, the MIMO
transmission system may transmit information identifying the QAM type of
each transmission signal in the transmission signal and the QAM type
identification information may be included in a preamble portion of the
transmission signal. The MIMO reception system may determine the
combination of the QAM types of the reception signals from the QAM type
identification information of the transmission signals and perform MIMO
decoding on the reception signals based on the determination.

[0123] The following is a description of a MIMO encoder and a MIMO
encoding method that have low system complexity, high data transmission
efficiency, and high signal reconstruction (or restoration) performance
in various channel environments according to an embodiment of the present
invention.

[0124] The SM scheme is a method in which data is simultaneously
transmitted through a plurality of antennas without MIMO encoding. In
this case, the receiver can acquire information from data that is
simultaneously received through a plurality of receive antennas. The SM
scheme has an advantage in that the complexity of a Maximum Likelihood
(ML) decoder that the receiver uses to perform signal reconstruction (or
restoration) is relatively low since the decoder only needs to check a
combination of received signals. However, the SM scheme has a
disadvantage in that transmit diversity cannot be achieved at the
transmitting side. In the case of the SM scheme, the MIMO encoder
bypasses a plurality of input signals. In the following, such a bypass
process may be referred to as MIMO encoding.

[0125] The GC scheme is a method in which data is transmitted through a
plurality of antennas after the data is encoded according to a
predetermined rule (for example, according to an encoding method using
golden code). When the number of the antennas is 2, transmit diversity is
acquired at the transmitting side since encoding is performed using a
2×2 matrix. However, there is a disadvantage in that the complexity
of the ML decoder of the receiver is high since the ML decoder needs to
check 4 signal combinations.

[0126] The GC scheme has an advantage in that it is possible to perform
more robust communication than using the SM scheme since transmit
diversity is achieved. However, such a comparison has been made when only
the GC scheme and the SM scheme are used for data processing for data
transmission and, if data is transmitted using additional data coding
(which may also be referred to as outer coding), transmit diversity of
the GC scheme may fail to yield additional gain. This failure easily
occurs especially when such outer coding has a large minimum Hamming
distance. For example, the transmit diversity of the GC scheme may fail
to yield additional gain compared to the SM scheme when data is
transmitted after being encoded by adding redundancy for error correction
using a Low Density Parity Check (LDPC) code having a large minimum
Hamming distance. In this case, it may be advantageous for the broadcast
system to use the SM scheme having low complexity.

[0127]FIG. 10 shows an exemplary structure of a P1 symbol and an
exemplary structure of an AP1 symbol according to an embodiment of the
present invention.

[0128] P1 symbol is generated by having each of a front portion and an end
portion of an effective (or valid) symbol copied, by having a frequency
shift performed as much as +fsh, and by having the frequency-shifted
copies respectively positioned at a front portion (C) and an end portion
(B) of the effective symbol (A). In the present invention, the C portion
will be referred to as a prefix, and the B portion will be referred to as
a postfix. More specifically, P1 symbol is configured of a prefix
portion, an effective symbol portion, and a postfix portion.

[0129] In the same manner, AP1 symbol is generated by having each of a
front portion and an end portion of an effective (or valid) symbol
copied, by having a frequency shift performed as much as -fsh, and
by having the frequency-shifted copies respectively positioned at a front
portion (F) and an end portion (E) of the effective symbol (D). In the
present invention, the F portion will be referred to as a prefix, and the
E portion will be referred to as a postfix. More specifically, AP1 symbol
is configured of a prefix portion, an effective symbol portion, and a
postfix portion.

[0130] Herein, the two frequency-shift values +fsh, -fsh, which
are used in the P1 symbol and the AP1 symbol, may have the same absolute
value yet be given opposite signs. More specifically, the frequency-shift
is performed in opposite directions. And, the lengths C and F, which are
copied to the front portion of the effective symbol, may be set to have
different values. And, the lengths B and E, which are copied to the end
portion of the effective symbol, may be set to have different values.
Alternatively, the lengths C and F may be set to have different values,
and the lengths B and E may be set to have the same value, or vice versa.
According to another embodiment of the present invention, an effective
symbol length of the P1 symbol and an effective symbol length of the AP1
symbol may be differently determined. And, according to yet another
embodiment of the present invention, a CSS (Complementary Set Sequence)
may be used for tone selection and data scrambling within the AP1 may be
scrambled by AP1.

[0131] According to the embodiment of the present invention, the lengths
of C and F, which are copied to the front portion of the effective (or
valid) symbol, may be set to have different values, and the lengths of B
and E, which are copied to the end portion of the effective (or valid)
symbol, may also be set to have different values.

[0132] The C,B,F,E lengths according to the present invention may be
obtained by using Equation 1 shown below.

Length of C(TC)={Length of A(TA)/2+}

Length of B(TB)={Length of A(TA)/2-30}

Length of E(TF)={Length of D(TD)/2+15} [Expression 1]

Length of E(TE)={Length of D(TD)/2-15}

[0133] As shown in Equation 1, P1 symbol and AP1 symbol have the same
frequency shift value. However, each of the P1 symbol and the AP1 symbol
are given opposite signs. Additionally, in order to determine the lengths
of C and B, the present invention determines an offset value being added
to or subtracted from a value corresponding to the length of A
(TA)/2. And, in order to determine the lengths of F and E, the
present invention determines an offset value being added to or subtracted
from a value corresponding to the length of D (TD)/2. Herein, each
of the offset values is set up differently. According to the embodiment
of the present invention, the offset value of P1 symbol is set to 30, and
the offset value of AP1 symbol is set to 15. However, the values given in
the above-described examples are merely exemplary. And, therefore, it
will be apparent that the corresponding values may easily be varied or
changed by anyone skilled in the art. Thus, the present invention will
not be limited only to the values presented herein.

[0134] According to the present invention, by generating AP1 symbol and an
AP1 symbol to configure the structure shown in FIG. 10, and by inserting
the generated symbols to each signal frame, the P1 symbol does not
degrade the detection performance of the AP1 symbol, and, conversely, the
AP1 symbol does not degrade the detection performance of the P1 symbol.
Additionally, the detection performance of the P1 symbol is almost
identical to the detection performance of the AP1 symbol. Furthermore, by
configuring the symbols so that the P1 symbol and the AP1 symbol have
similar symbol structures, the complexity level of the receiver may be
reduced.

[0135] At this point, the P1 symbol and the AP1 symbol may be transmitted
consecutively, or each of the symbols may be allocated to different
positions within the signal frame and may then be transmitted. And, in
case the P1 symbol and AP1 symbol are each allocated to a different
position within the signal frame, so as to be transmitted, a high time
diversity effect may be gained with respect to the preamble symbol.
According to the embodiment of the present invention, the P1 symbol and
the AP1 symbol are consecutively transmitted. In that case, the AP1
symbol, according to FIG. 3, transmits information necessary for decoding
signaling information spread in a pilot pattern or a frame of a data
area. It can be generated in FIG. 5.

[0136]FIG. 11 shows an exemplary structure of a P1 symbol detector
according to an embodiment of the present invention.

[0137] The P1 symbol detector may be included in the OFDM demodulator
(107100) explained in FIG. 2.

[0138] Herein, the P1 symbol detector may also be referred to as a C-A-B
preamble detector. The P1 symbol detector may include down shifter
(307101), 1st conjugator (307103) and 2nd delayer (307106).

[0139] The down shifter (307101) performs inverse modulation by
multiplying e-j2πfSH' by the input signal. When inverse
modulation is performed by the down shifter (307101), the signal being
frequency-shifted and inputted is recovered to the original signal. The
inverse modulated signal may be outputted to a 1st delayer (307102)
and a 2nd conjugator (307107).

[0140] The 1st delayer (307102) delays the inverse-modulated signal
by a length of part C (TC) and then outputs the delayed signal to
the 1st conjugator (307103). The 1st conjugator (307103)
performs complex-conjugation on the signal, which is delayed by a length
of part C (TC). Then, the 1st conjugator (307103) multiplies
the input signal by the complex-conjugated signal, thereby outputting the
processed signal to a 1st filter (307104). The 1st filter
(307104) uses a running average filter having the length of
TR=TA, so as to remove (or eliminate) any excessively and
unnecessarily remaining modulation elements, thereby outputting the
processed signal to a 3rd delayer (307105). The 3rd delayer
(307105) delays the filtered signal by a length of part A (i.e.,
effective (or valid) symbol) (TA), so as to output the delayed
signal to a multiplier (307109).

[0141] The 2nd delayer (307106) delays the input signal by a length
of part B (TB) and then outputs the delayed signal to the 2nd
conjugator (307107). The 2nd conjugator (307107) performs
complex-conjugation on the signal, which is delayed by a length of part B
(TB). Then, the 2nd conjugator (307107) multiplies the
complex-conjugated signal by an inverse-modulated signal, thereby
outputting the processed signal to a 2nd filter (307108). The
2nd filter (307108) uses a running average filter having the length
of TR=TA, so as to remove (or eliminate) any excessively and
unnecessarily remaining modulation elements, thereby outputting the
processed signal to the multiplier (307109).

[0142] The multiplier (307109) multiplies the output of the 2nd
filter (307109) by a signal, which is delayed by a length of part A
(TA). Thus, a P1 symbol may be detected from each signal frame of
the received broadcast signal.

[0143] Herein, the length of part C (TC) and the length of part B
(TB) may be obtained by applying Equation 1 shown above.

[0144]FIG. 12 shows an exemplary structure of an AP1 symbol detector
according to an embodiment of the present invention.

[0145] The AP1 symbol detector may be included in the OFDM demodulator
(107100) explained in FIG. 2.

[0146] Herein, the AP1 symbol detector may also be referred to as an F-D-E
preamble detector. The AP1 symbol detector may include down shifter
(308101), 1st conjugator (308103) and 2nd delayer (308106). The
AP1 symbol detector may receive a signal inputted to broadcast signal
receiver or a signal outputted from the P1 symbol detector explained in
FIG. 11.

[0147] The up-shifter (308101) performs inverse modulation by multiplying
e-j2πfSH' by the input signal. When inverse modulation is
performed by the up-shifter (308101), the signal being frequency-shifted
and inputted is recovered to the original signal. More specifically, the
up-shifter (308101) of FIG. 47 has the same structure as the down-shifter
(307101) of the P1 symbol detector (306601). However, the frequency
direction of each inverse modulation process is completely opposite to
one another. The signal that is inverse modulated by the up-shifter
(308101) may be outputted to a 1st delayer (308102) and a 2nd
conjugator (308107).

[0148] The 1st delayer (308102) delays the inverse-modulated signal
by a length of part F (TF) and then outputs the delayed signal to
the 1st conjugator (308103). The 1st conjugator (308103)
performs complex-conjugation on the signal, which is delayed by a length
of part F (TF). Then, the 1st conjugator (308103) multiplies
the input signal by the complex-conjugated signal, thereby outputting the
processed signal to a 1st filter (308104). The 1st filter
(308104) uses a running average filter having the length of
TR=TD, so as to remove (or eliminate) any excessively and
unnecessarily remaining modulation elements, thereby outputting the
processed signal to a 3rd delayer (308105). The 3rd delayer
(308105) delays the filtered signal by a length of part D (i.e.,
effective (or valid) symbol) (TD), so as to output the delayed
signal to a multiplier (308109).

[0149] The 2nd delayer (308106) delays the input signal by a length
of part E (TE) and then outputs the delayed signal to the 2nd
conjugator (308107). The 2nd conjugator (308107) performs
complex-conjugation on the signal, which is delayed by a length of part E
(TE). Then, the 2nd conjugator (308107) multiplies the
complex-conjugated signal by an inverse-modulated signal, thereby
outputting the processed signal to a 2nd filter (308108). The
2nd filter (308108) uses a running average filter having the length
of TR=TD, so as to remove (or eliminate) any excessively and
unnecessarily remaining modulation elements, thereby outputting the
processed signal to the multiplier (308109).

[0150] The multiplier (308109) multiplies the output of the 2nd
filter (308109) by a signal, which is delayed by a length of part D
(TD). Thus, an AP1 symbol may be detected from each signal frame of
the received broadcast signal. Herein, the length of part F (TF) and
the length of part E (TE) may be obtained by applying Equation 1
shown above.

[0151] As shown in FIG. 3, a frame according to an embodiment of the
present invention comprises a preamble area and a data area. The preamble
are comprises a P1 and P2 and there can be a plurality of data symbols in
the data area. Also, as the designer intends, there can be an AP1 in the
preamble area.

[0152] Then, P1 signaling information is transmitted by the P1 symbol, the
AP1 signaling information is transmitted by the AP1 symbol, and L1-pre
and L1-post signaling information is transmitted by the P2 symbol.

[0153] An embodiment of a broadcast signal transmitter or receiver for
MIMO processing is as follows.

[0155] The input processor 101200 of the broadcast signal transmitter
executes FEC encoding for transmitting data in a form of block. The BICM
encoder 101300 performs encoding for correcting errors. The frame builder
101400 performs mapping data in a frame, and the OFDM generator 101500
performs OFDM demodulating in the frame-mapped data into symbol units and
transmit the data. Devices in the broadcast signal receiver can perform
reverse-functioning corresponding to the counterpart devices in the
transmitter.

[0156] The present invention suggests a broadcast signal transmitter or
receiver that independently applies MISO or MIMO processing for each PLP
from a plurality of PLP inputs. According to the present invention, the
present invention can effectively adjust the quality of service (QOS) or
services from PLP in a physical layer.

[0157] Four embodiments for performing MISO/MISO processing in a plurality
of signals from the transmitter and receiver through a plurality of
antennas are as follows. Individual embodiments can be distinguished from
each other according to whether MISO/MIMO processing for each PLP is
processed or according to the position of MISO/MIMO processing. A brief
description of individual embodiments is as follows.

[0158] A first embodiment is about a broadcast signal transmitter or a
corresponding receiver independently performing MISO or MIMO processing
for each PLP data input during a BICM encoding process.

[0159] A second embodiment is about another broadcast signal transmitter
or a corresponding receiver independently performing MISO or MIMO
processing for each PLP data input during a BICM encoding process.

[0160] A third embodiment is about a broadcast signal transmitter or a
corresponding receiver independently performing MISO or MIMO processing
for mapped PLP data input during a OFDM generating process.

[0161] A fourth embodiment is about a broadcast signal transmitter or a
corresponding receiver independently performing MISO or MIMO processing
for each PLP data input during a BICM encoding process, wherein an OFDM
generator performs MISO processing in MISO PLP data and L1-signaling
information.

[0162] In more detail, the BICM encoder of the broadcast signal
transmitter according to the first embodiment performs MISO encoding or
MIMO encoding in PLP data after constellation-mapping, cell interleaving,
and time interleaving. Also, the BICM decoder of the broadcast signal
transmitter according to the first embodiment can reverse the whole
process. According to the second embodiment, the BICM encoder of the
broadcast signal transmitter according to the second embodiment performs
MISO encoding or MIMO encoding in PLP data after constellation-mapping,
and then performs cell interleaving and time interleaving. Also, the BICM
decoder of the broadcast signal transmitter according to the second
embodiment can reverse the whole process.

[0163] According to the third embodiment, the OFDM generator of the
broadcast signal transmitter performs MISO or MIMO encoding in PLP data
transmitted from a frame builder. In addition, an OFDM demodulator of the
broadcast signal receiver according to a third embodiment of the present
invention may perform a reverse process of the OFDM generator of the
broadcast transmitter.

[0164] According to the fourth embodiment, the BICM encoder of the
broadcast signal transmitter according to the fourth embodiment performs
MISO encoding or MIMO encoding in PLP data after time interleaving or
constellation-mapping. Also, the OFDM generator of the broadcast signal
transmitter performs MISO encoding in MISO PLP data for MISO processing
and L1-signaling information. The BICM decoder of the broadcast signal
receiver and the OFDM demodulator of the broadcast signal transmitter
according to the fourth embodiment can reverse the whole process.

[0165] A broadcast signal transmitter/receiver according to each
embodiment is as follows. The broadcast signal transmitter/receiver can
perform MIMO processing for a plurality of signals through a plurality of
antennas. The broadcast signal transmitter/receiver with two signals by
two antennas is described below.

[0166] FIG. 13 and FIG. 14 show an input process that the broadcast signal
transmitter comprises in common. Further description is as follows.

[0167] FIG. 13 shows an input processor of the broadcast signal
transmitter according to an embodiment.

[0169] The input interface module 601110 in the input processor performing
a single PLP performs mapping by distinguishing the input bit stream in a
logical unit to perform FEC (BCH/LDPC) encoding at the end of the BICM
encoder. The CRC-9 encoder 601120 performs CRC encoding in the mapped bit
stream and a BB header insertion module 1050 inserts a BB header in the
data field. In that case, the BB header includes all adaptation type
(TS/GS/IP) information, user packet length information, and data field
length.

[0170] Also, if the input data does not have a BB frame for FEC encoding,
the stream adaptation block 601200 generates a padding insertion unit and
a Pseudo Random Binary Sequence (PRBS) and includes a BB scrambler 601220
randomizing data computed by the PRBS and XOR. Such a move by the BB
scrambler 601220 can ultimately lower the Peak-to-Average Power Ratio of
the OFDM-modulated signal.

[0171]FIG. 14 shows a mode adaptation module implementing a plurality of
PLP as an input processor according to an embodiment of the present
invention.

[0173] The input stream synchronizer 602200 inserts timing information
necessary for restoring input stream clock reference information (ISCR),
transport stream (TS) or generic stream (GS). The compensating delay
module 602300 synchronizes a group of PLP based on the timing
information. The null packet deletion module (602400) deletes null packet
that is unnecessarily transmitted and inserts the number of the deleted
null packets based on the deleted position.

[0174]FIG. 15 shows a stream adaptation module implementing a plurality
of PLP as an input processor according to an embodiment of the present
invention.

[0175] The stream adaptation module in FIG. 17 receives PLP-based data in
which mode adaptation of FIG. 14 was performed from the mode adaptation
module of FIG. 14, such that it can perform stream adaptation as shown in
the following description.

[0176] The scheduler 603100 performs scheduling for the MIMO transmitting
system using a plurality of antennas including dual polarity and
generates parameters for a demultiplexer, a cell interleaver, a time
interleaver. Also, the scheduler 603100 transmits L1-dynamic signaling
information for the current frame besides in-band signaling, and performs
cell mapping based on the scheduling.

[0177] A plurality of a 1-frame delay module 603200 executing a plurality
of PLP delays one frame so that scheduling information of the next frame
for in-band signaling can be included in the current frame. A plurality
of in-band signaling/padding insertion module inserts L1-dynamic
signaling information to the delayed data. Also, if there is any room for
padding, the in-band signaling/padding insertion module 603300 inserts
padding bits and in-band signaling information into the padding area.
And, the BB scrambler 603400 generates a pseudo random binary sequence
(PRBS) as shown in FIG. 29 and randomizes the data by computing the PRBS
with XOR.

[0178] The stream adaption module in FIG. 15 generates L1-signaling
information transmitted by the preamble symbol of the frame or the spread
data symbol. Such L1-signaling information includes L1-pre signaling
information and L1-post signaling information. The L1-pre signaling
information includes parameters necessary for performing the L1-post
signaling information and static L1-signaling information, and the
L1-post signaling information includes the static L1-signaling
information and dynamic L1-signaling information. The L1-signaling
generator 603500 can transmit the generated L1-pre signaling information
and L1-post signaling information. The transmitted L1-pre signaling
information and L1-post signaling information is scrambled by each BB
scramble 603600, 603700. Also, according to another embodiment, the L1
signaling generator 603500 transmits L1-signaling information having
L1-pre signaling and L1-post signaling information and scrambles
L1-signaling information transmitted by one BB scrambler.

[0179] FIG. 16 to FIG. 19 shows a structure block of a broadcast signal
transmitter according to an embodiment. Further description is as
follows.

[0180] FIG. 16 shows a BICM encoder according to an embodiment of the
present invention.

[0181] The BICM encoder shown in FIG. 16 is an embodiment of the BICM
encoder 101300 in FIG. 1.

[0182] The BICM encoder according to the first embodiment performs
bit-interleaving in a plurality of PLP data after performing
input-processing, L1-pre signaling information, and L1-post signaling
information, and encoding for correcting errors.

[0183] Also, the BICM encoder independently performs MISO or MIMO encoding
in PLP data. In addition, the BICM encoder according to a first
embodiment of the present invention may perform MISO encoding and MIMO
encoding upon completion of constellation mapping.

[0184] The BICM encoder in FIG. 16 includes a first BICM encoding block
607100 performing MISO encoding in PLP data, a second BICM encoding block
607200 performing MIMO encoding in PLP data, and a third BICM encoding
block 607300 performing MIMO encoding in signaling information. The third
BICM encoding block 604300 performing MIMO encoding in signaling
information. However, as the signaling information includes information
necessary for restoring PLP data in a frame from the receiver, more
robustness is required between the transmitter and receiver compared to
PLP data. Thus, an embodiment of the present invention is the MISO
process performing the signaling information. The description of data
performing process for each block is as follows.

[0185] First, the first BICM encoding block 604100 includes a BICM encoder
604100, a FEC (Forward Error Correction) encoder 604110, a
bit-interleaver 604120, a first demultiplexer 604130, a constellation
mapper 604140, a MISO encoder 604150, a cell interleaver
604160-1,604160-2 and a time interleaver 604170-1, 604170-2.

[0186] The FEC encoder 604110 performs BCH encoding and LDPC encoding in
PLP data after performing input processing with redundancy to correct
channel errors from the receiver. The bit-interleaver 604120 prepares to
have robustness for bust errors by performing bit-interleaving in the
FEC-encoded PLP data by each FEC block unit. In that case, the bit
interleaver can perform bit interleaving by using two FEC block units.
When using two FEC blocks, a pair of cell units may be generated from two
different FEC blocks in the frame-builder. Thus, the broadcast signal
receiver may improve the reception by ensuring the diversity of FEC
blocks.

[0187] A first demultiplexer 604130 can perform demultiplexing in the
bit-interleaved PLP data into one FEC block unit. In that case, the first
demultiplexer 604130 uses two FEC blocks and performs demultiplexing.
When using the two blocks, pairs of cells in the frame builder may be
generated from different FEC blocks. Thus, the receiver can improve
reception by ensuring the diversity of FEC blocks.

[0188] The constellation mapper 604140 performs mapping in the
bit-demultiplexed PLP data into symbol units. In that case, the
constellation mapper 604140 can rotate a certain angle depending on the
modulation type. The rotated constellation mappers can be expressed in
I-phase (In-phase) and Q-phase (Quadrature-phase), and the constellation
mappers can delay only the Q-phase for a certain value. Then, the
constellation mapper 604140 performs re-mapping in the In-phase element
with the delayed Q-phase element.

[0190] The cell interleaver 604160-1, 604160-2 performs interleaving in
the re-mapped data into cell units, and the time interleaver 604170-1,
604170-2 performs interleaving in the cell-interleaved PLP data into time
units. In that case, the time interleaver 604160 uses two FEC blocks for
interleaving. Through this process, as pairs of cells are generated from
two different FEC blocks, the receiver can improve reception by ensuring
the diversity of the FEC blocks.

[0191] The second BICM encoding block 604200 includes a FEC encoder
604210, a bit-interleaver 604220, a second demultiplexer 604230, a first
constellation mapper 604240-1 and a second constellation mapper 604240-2,
and a MIMO encoder 604250, a first cell interleaver 604260-1 and a second
interleaver 604260-2, and a first time interleaver 604270-1 and a second
cell interleaver 604270-2.

[0192] The FEC encoder 604210 and the bit-interleaver 604220 can perform
the same function as the FEC encoder 604110 and the bit-interleaver
604120 of the MISO method.

[0193] The second demultiplexer 604230 can transmit the PLP data by
demultiplexing to two routes necessary for MIMO transmission in addition
to performing the same function as the first demultiplexer 604130 of the
MISO method. In that case, the character of the data transmission for
each route may be different. Thus, the second demultiplexer can randomly
allocate the bit-interleaved PLP data into each route.

[0194] The first constellation mapper 604240-1 and the second
constellation mapper 604240-2 can operate the same function as the
constellation mapper 604140 of the MISO method.

[0195] The MIMO encoder 604270 performs MIMO encoding in the
time-interleaved PLP data from by using MIMO encoding matrix and transmit
MIMO PLP data to two routes (STx_m, STx_m+1). The MIMO encoding matrix of
the present invention includes a spatial multiplexing, a Golden code
(GC), a full-rate full diversity code, and a linear dispersion code.

[0196] The first cell interleaver 604260-1 and the second cell interleaver
604260-2 can perform cell-interleaving in only a half of the PLP data in
one of the FEC blocks from the routes. Thus, the first cell interleaver
604260-1 and second cell interleaver 604260-2 can operate the same as the
one cell interleaver. Also, in order to execute data from a plurality of
routes, as the first cell interleaver 604260-1 and the second cell
interleaver 604260-2 are not allocated additional memory, there is an
advantage of performing cell interleaving by using the memory of the one
cell interleaver.

[0197] The first time interleaver 604270-1 and the second time interleaver
604270-2 can operate the same as the time interleaver 604170-1, 604170-2
of the MISO method. In that case, the first time interleaver 604270-1 and
the second time interleaver 604270-2 can be performed the same time
interleaving or a different time interleaving.

[0199] Thus, the third BICM encoding block 604300 includes a first
encoding block 604400 executing the L1-pre signaling information and the
second encoding block 604500 executing the L1-post signaling information.

[0201] The L1-pre signaling information includes information necessary for
decoding L1-post signaling information and the L1-post signaling
information includes information necessary for restoring data transmitted
from the receiver.

[0202] That is, the receiver needs to decode the L1-pre signaling
information quickly and correctly for decoding the L1-signaling
information and the data. Thus, the receiver of the present invention
does not perform bit-interleaving and de-multiplexing for the L1-pre
signaling information in order to perform the fast decoding.

[0203] The description of first encoding block 604400 and the second
encoding block 604500 is omitted because they perform the same function
as the first BICM block 604100.

[0204] As a result, to execute the L1-pre signaling information, the first
encoding block 604400 performs MISO encoding in the L1-pre signaling
information and transmits the free-signaling data to two routes (STx_pre,
STx_pre+1). Also, to execute L1-post signaling information the second
encoding block 604500 performs MISO encoding in the L1-post signaling
information and transmits the L1-post signaling data to two routes
(STx_post, STx_post+1).

[0205]FIG. 17 shows a BICM encoder according to another embodiment of the
present invention.

[0206] The BICM encoder shown in FIG. 17 according to the second
embodiment is another embodiment of the BICM encoder 101300 in FIG. 1.

[0207] The BICM encoder according to the second embodiment performs
bit-interleaving in a plurality of PLP data after performing
input-processing, L1-pre signaling information, and L1-post signaling
information, and encoding for correcting errors.

[0210] As the BICM encoding blocks in FIG. 17 operate the same as the BICM
encoding blocks in FIG. 16, further description of them is omitted.
However, the BICM encoding blocks of the MISO encoder 607120, 607420,
607520 and the MIMO encoder 607220 are positioned at the end of the time
interleaver 607110, 607210-1-2, 607410 and 607510 which is
distinguishable from the BICM encoding blocks according to the first
embodiment.

[0211] Although not illustrated in FIG. 17, the BICM encoder according to
the third embodiment of the present invention may include a first BICM
encoding block for processing of MISO PLP data to be MISO encoded, a
second BICM encoding block for processing of MIMO PLP data to be MIMO
encoded, and a third BICM encoding block for processing of signaling
information to be MISO encoded. The BICM encoding blocks according to the
third embodiment operate in the same way as the BICM encoding blocks
according to the first embodiment illustrated in FIG. 16, and thus, a
detailed description thereof is omitted. However, the BICM encoding
blocks according to the third embodiment is different from the BICM
encoding blocks according to the first embodiment in that the BICM
encoding blocks according to the third embodiment do not include a MISO
encoder and a MIMO encoder.

[0212] In addition, the BICM encoder according to the fourth embodiment of
the present invention is almost the same as the BICM encoder according to
the third embodiment, except that the BICM encoder performs MIMO encoding
on MIMO PLP data to be processed using the MIMO scheme. That is, the BICM
encoder according to the fourth embodiment of the present invention may
include a first BICM encoding block for processing MISO PLP data to be
MISO encoded, a second BICM encoding block for processing of MIMO PLP
data to be MIMO encoded, and a third BICM encoding block for processing
of signaling information to be MISO encoded. Here, the third BICM
encoding block may include a first encoding block for processing of
L1-pre signaling information and a second encoding block for processing
of L1-post signaling information. In particular, the first BICM encoding
block according to the fourth embodiment may not include a MISO encoder
and the second 2 BICM encoding block may include a MIMO encoder. In this
case, the MIMO encoder may be positioned behind a time interleaever as in
the first embodiment, or may be positioned behind a constellation mapper
according to the second embodiment as in the second embodiment. The
position of the MIMO encoder may be changed according to a designer's
intention.

[0213] FIG. 18 shows a frame builder according to an embodiment of the
present invention.

[0214] The frame builder shown in FIG. 18 is an embodiment of the frame
builder 101400 shown in FIG. 1.

[0216] Each data is inputted into the frame builder. In that case, as
shown in FIG. 18, the frame builder includes a first route receiving the
BICM encoded data from STx--0 to STx_post, and a second route
receiving the BICM encoded data from STx--0+1 to Stx_post+1. The
data received in the first route is transmitted through a first antenna
(Tx--1) and the data in the second route is transmitted through a
second antenna (Tx--2).

[0217] As shown in FIG. 18, the frame builder according the first
embodiment includes a first frame building block 605100 executing the
data from the first route and a second frame building block 605200
executing the data from the second route. The first frame building block
605100 includes a first delay compensator 604110, a first pair-wise cell
mapper 605120, and a first pair-wise frequency interleaver 605300-1, and
a second frame building block 605200 includes a second delay compensator
605100-2 executing the data from the second route, a second pair-wise
cell mapper 605200-2, and a second pair-wise frequency interleaver
605300-2.

[0218] The first pair-wise cell mapper 605120 and the first pair-wise
frequency interleaver 605130, or the second pair-wise cell mapper 605120
and the second pair-wise frequency interleaver 605310 operate
independently but the same functions in the first and the second routes
respectively.

[0219] A method of performing data in the first frame building block
605100 and the second frame building block 605200.

[0220] The first delay compensator 605110 and the second delay compensator
605110 can compensate the L1-pre signaling data or the L1-post signaling
data for the delay in the first frame and by the BICM encoder 604300. The
L1-signaling information can include information not only in the current
frame but also in the next frame. Thus, during the input processing, the
L1-signaling information can be delayed one frame as opposed to PLP data
inputted in the current frame. Through this process, one frame of the
L1-signaling information having information about the current and the
next frames.

[0221] The first pair-wise cell mapper 605120 and the second pair-wise
cell mapper 605220 can perform mapping in the PLP data and the
L1-signaling data in symbol units into cell units in a frame in the
sub-carrier of the OFDM symbols.

[0222] In that case, the PLP data includes a common PLP DATA, a MISO/MIMO
encoded PLP data and a sub-slice processor module 605120-1-2 performs
frame-mapping in the PLP data in cell units for the diversity effect.

[0223] Also, the first pair-wise cell mapper 605120 and the second
pairwaise cell mapper 605220 can perform frame-mapping in two consecutive
inputted cells in pairs.

[0224] For the better restoration performance of MISO signals, coherence
between MSI transmitting channels should be secured when performing MISO
encoding. Thus, in order to secure coherence, the first pair-wise cell
mapper 605120 and the second pair-wise cell mapper 605220 pair up cells
generated from the same PLP and perform OFDM modulating in the paired-up
cells. Then coherence between the channels will be maximized. In other
words, according to an embodiment of the present invention, as the MISO
encoder is positioned in the front of the BICM encoder, the structure of
the frames is in pairs considering such MISO encoding process.

[0225] As mentioned above, when performing bit-interleaving or time
interleaving by the bit-interleaver 604120 and the time interleaver
604160 using two FEC blocks, two paired up cells can be generated from
two different FEC blocks. As the receiver ensures diversity, higher
reception can be obtained. The first pair-wise frequency interleaver
605130 and the second pair-wise frequency interleaver 605230 perform
frequency interleaving in the data in cell units from each route and
transmits the frequency-interleaved data to the OFDM generator through
each route.

[0226] In that case, the first pair-wise frequency interleaver 605130 and
the second pair-wise frequency interleaver 605230 pair up two consecutive
cells in interleaving units and then perform frequency interleaving. This
is to maximize coherence between channels.

[0227] The frame builder illustrated in FIG. 18 may be applied to the
first and second embodiments of the present invention. According to the
third and fourth embodiments of the present invention, the frame builder
may include a first cell mapper and a second cell mapper instead of the
first pair-wise cell mapper 605120 and the second pair-wise cell mapper
605220, and include a first frequency interleaver and a second frequency
interleaver instead of the first pair-wise frequency interleaver 605130
and the second pair-wise frequency interleaver 605230.

[0228] According to the third embodiment, after frequency interleaving,
that is, after MISO/MIMO encoding in the OFDM generating process,
MIMO/MISO encoding can be done in OFDM symbol units. If the MISO PLP data
cells and MIMO PLP data cells are mapped in the same OFDM symbol, the
OFDM generator cannot perform MISO/MIMO encoding independently. Thus, the
first cell mapper and the second cell mapper dose not map the MISO/MIMO
PLP data in the same OFDM symbol.

[0229] Also, in order to simplify the transmitting system, the first and
second cell mappers according to the third embodiment operate the same.

[0230] But, although the MISO PLP data, L1-pre and post signaling data is
transmitted from the first route only, the MIMO PLP data can be from the
first and the second routes. Therefore, depending on the data inputted,
the performance of the cell mapper is different.

[0231] More detailed description is as follows.

[0232] First, the first cell mapper and the second cell mapper receive the
same MISO PLP data from the first route and the same L1-pre and post
signaling data from the delay compensator. In that case, the first cell
mapper and the second cell mapper perform mapping in the inputted data to
be allocated into a sub-carrier of the OFDM symbol.

[0233] Second, among the first cell mapper and the second cell mapper, the
first cell mapper only receives the MISO PLP data and the delayed
compensated L1-pre and post signaling data. In that case, the second cell
mapper performs mapping only for the MIMO PLP.

[0234] The first frequency interleaver and the second frequency
interleaver perform frequency interleaving in the inputted data by cell
units and transmits the data to the OFDM generator.

[0235] In that case, the first frequency interleaver and the second
frequency interleaver perform frequency interleaving in the OFDM symbol
into interleaving units. Also, if the second cell mapper 619210 receives
MIMO PLP data only, the second frequency interleaver also performs
interleaving in MIMO PLP data only.

[0236] FIG. 19 shows an OFDM generator according to an embodiment of the
present invention.

[0237] The OFDM generator in FIG. 19 is an embodiment of the OFDM
generator 101500 shown in FIG. 1.

[0238] The present invention transmits broadcast signals by the MISO/MIMO
method through two antennas. The OFDM generator in FIG. 19 receives and
demodulates the broadcast signals through a first and a second route. It
then transmits the signals to two antennas (Tx1, Tx2).

[0239] A first OFDM generating block 606800 modulates the broadcast
signals through the first antenna (Tx1) and a second OFDM generating
block 606900 modulates the broadcast signals through the second antenna
(TX2).

[0240] If channel correlation between the first and second antennas is
large, transmitted signals can apply polarity depending on the channel
correlation. In the present invention, such a method is called polarity
multiplexing MIMO. The first antenna is called "vertical antenna" and the
second antenna is called "horizontal antenna". The first OFDM generating
block 606800 performs OFDM modulating in broadcast signals through the
first antenna (Tx1) and the second transmitter 606900 performs OFDM
modulating in the broadcast signals from the first route and transmits
the signals to the second antenna (Tx2).

[0241] Modules including the first OFDM generating block 606800 and the
second OFDM generating block 606900 are as follows.

[0244] Thus, modules in the first OFDM generating block 606800 will be
illustrated in more detail. The pilot insertion module inserts a pilot of
the predetermined pilot pattern into a frame and transmits it to the IFFT
module 606200-1. The pilot pattern information is transmitted with AP1
signaling information or L1-signaling information.

[0245] The IFFT module 606200-1 performs IFFT algorithm in the signals and
transmits them to the PAPR module 606300-1.

[0246] The PAPR module 606300-1 reduces PAPR of the signals in a time
domain and transmits them to the GI insertion module 606400-1. Also,
feedback on necessary information based on the PAPR reduction algorithm
is given to the pilot insertion module 606100-1.

[0247] The GI insertion module 606400-1 copies the end of the effective
OFDM symbol, inserts guard intervals in cyclic prefix to each OFDM
symbol, and transmits them to the P1 symbol insertion module 606500-1.
The GI information can be transmitted through the P1 signaling
information or L1-pre signaling information.

[0248] The P1 and AP1 symbol are inserted in every frame of the P1
insertion module in the OFDM generator. That is, the P1 insertion module
can insert more than two preamble symbols in every frame. When using more
than two preamble symbols, burst fading that can happen in the mobile
fading conditions will be more strengthened and signal detection
performance will be improved.

[0249] The P1 symbol insertion module 606500-1 inserts a P1 symbol in the
beginning of each frame and transmits it to the AP1 symbol insertion
module 606600-1.

[0250] The AP1 symbol insertion module 606600-1 inserts an AP1 symbol at
the end of the P1 symbol and transmits it to the DAC 606700-1.

[0251] The DAC 606700-1 converts the signal frame having the P1 symbol to
an analog signal and transmits it to the transmitting antenna (Tx1).

[0252] The OFDM generator shown in FIG. 19 may be applied to the first and
second embodiments of the present invention.

[0253] Although not shown in FIG. 19, according to the third embodiment of
the present invention, the OFDM generator may include a MISO/MIMO
encoder, a first OFDM generating block, and a second OFDM generating
block. The first OFDM generating block and the second generating block
according to the third embodiment of the present invention may perform
the same operations as those of the first OFDM generating block 606800
and the second OFDM generating block 606900.

[0254] If the input data is MISO PLP data or L1-pre and post signaling
data from the first and second routes, the MIMO/MISO encoder 603100
performs MISO encoding in the data into OFDM symbol units by using MISO
encoding matrix and transmits it to the first and second generating
blocks 620200, 620300. In that case, the input data is transmitted from
either of the first or second route. According to an embodiment, the MISO
encoding matrix can include an OSTBC (Orthogonal Space-Time Block
Code)/OSFBC(Orthogonal Space Frequency Block Code/Alamouti code).

[0255] If data from the first and second routes is MIMO PLP data, the
MIMO/MISQ encoder performs MIMO encoding in the data into OFDM symbol
units by using MIMO encoding matrix and transmits it to the first and
second OFDM generating blocks. The MIMO encoding matrix of the present
invention includes a spatial multiplexing, a Golden code (GC), a
full-rate full diversity code, and a linear dispersion code. Also, the
MIMO encoder performs MIMO encoding by using MIMO encoding matrix.

[0256] In addition, the OFDM generator according to the fourth embodiment
of the present invention may include a MISO encoder, a first OFDM
generating block, and a second OFDM generating block. The first OFDM
generating block and the second generating block according to the fourth
embodiment of the present invention may perform the same operations as
those of the first OFDM generating block 606800 and the second OFDM
generating block 606900.

[0257] The MISO encoder performs MISO encoding in the
frequency-interleaved MISO PLP data, L1-pre signaling data and L1-post
signaling data. The MISO encoder operates the same as the MIMO/MISO
encoder according to the third embodiment. In addition, if the MIMO
encoded MIMO PLP data is inputted, it may be bypassed and the MISO
encoder may perform MISO encoding in the MIMO encoded MIMO PLP data.

[0258] FIG. 20 and FIG. 24 show a structure block of the broadcast signal
receiver according to an embodiment of the present invention.

[0259] FIG. 20 shows an OFDM demodulator according to an embodiment of the
present invention.

[0260] FIG. 20 shows a drawing of the OFDM demodulator according to an
embodiment of the OFDM demodulator 107100 illustrated in FIG. 2.

[0261] According to an embodiment of the present invention, the present
invention requires two antennas, Rx1 and Rx2, to receive transmitted
signals by MIMO/MISO. The OFDM demodulator shown in FIG. 20 can perform
OFDM demodulation through the Rx1 and Rx2 antennas.

[0262] A block demodulating transmitted signals through a first antenna
(Rx1) is called a first OFDM demodulating block 610100 and a block
demodulating transmitted signals through a second antenna (Rx2) is called
a second OFDM demodulating block 610200.

[0263] In addition, the present invention can utilize polarity
multiplexing MIMO according to an embodiment of the present invention.
The first OFDM demodulating block 610100 performs OFDM demodulation in
the broadcast signals transmitted through the first antenna (Rx1) and
outputs the signals by a frame demapper to a first route, and the second
demodulating block 610200 performs OFDM demodulating in the broadcast
signals transmitted through the second antenna (Rx2) and outputs the
signals by a frame demapper to a second route.

[0264] Also, the OFDM according to the first embodiment in FIG. 20 can
perform the reverse process of the OFDM generator illustrated in FIG. 19.

[0265] The first OFDM demodulating block 610100 and the second OFDM
demodulating block 610200 included in OFDM demodulator according to an
embodiment of the present in invention including are as follows.

[0271] The P1 symbol detection module 610130 extracts P1 symbols in the P1
signaling information and decodes the P1 signaling information. Also, the
P1 symbol detection module 610130 transmits the decoded P1 signaling
information to the synchronizing module 610150 and a system controller
(not shown in the drawing). The system controller determines which frame
the received signal has by using the decoded P1 signaling information and
controls other devices.

[0272] The AP1 symbol detection module 610140 extracts AP1 symbols in the
AP1 signaling information and decodes the AP1 signaling information.
Also, the AP1 symbol detection module 610140 transmits the decoded AP1
signaling information to the synchronizing module 610150 and a system
controller (not shown in the drawing). The system controller determines
the pilot pattern information in the current frame and L1-pre spread
interval information by using the decoded AP1 signaling information.

[0273] The synchronizing module 610150 performs time and frequency
synchronizing by using the decoded P1 signaling information and the AP1
signaling information.

[0274] The GI cancellation module 610160 deletes guard intervals included
in the synchronized signals and transmits them to the FFT module 610170.

[0275] The FFT module 610170 converts the signals from the time domain to
the frequency domain by performing FFT algorithm.

[0276] The channel detection module 610180 detects a transmitting channel
from the transmitting antenna to the receiving antenna by using pilot
signals having the converted signals. Then, the channel detection module
610180 can additionally perform equalizing for each of the received data.
Signals that are converted into the frequency domain will be inputted in
the frame demapper.

[0277] The OFDM demodulator illustrated in FIG. 20 may be applied to the
first and second embodiments of the present invention.

[0278] Although not illustrated in FIG. 20, according to the third
embodiment of the present invention, the OFDM demodulator may include a
first OFDM demodulating block, a second OFDM demodulating block, and a
MISO/MIMO decoder. The first OFDM demodulating block and the second OFDM
demodulating block according to the third embodiment of the present
invention may perform the same operations as those of the first OFDM
demodulating block 610100 and the second OFDM demodulating block 610200.
However, the OFDM demodulator according to the third embodiment may
include a MIMO/MISO decoder 626300, a detailed operation of which will be
described below.

[0279] The OFDM according to the fourth embodiment of the present
invention may include a first OFDM demodulating block, a second OFDM
demodulating block, and a MISO decoder. The first OFDM demodulating block
and second OFDM demodulating block according to the fourth embodiment of
the present invention may perform the same operations as those of the
first OFDM demodulating block 610100 and the second OFDM demodulating
block 610200.

[0280]FIG. 21 shows a frame demapper according to an embodiment of the
present invention.

[0281] The frame demapper in FIG. 21 is an embodiment of the frame
demapper 107200 in FIG. 2.

[0282] The frame demapper illustrated in FIG. 21 includes the first frame
demapping block 611100 executing data from a first route and a second
frame demapping block 611200 executing data from a second route. The
first frame demapping block 611100 includes a first pair-wise frequency
deinterleaver 611110 and a first pair-wise cell demapper 611120, and the
second demapping block 611200 includes a second pair-wise frequency
deinterleaver 611210 and a second pair-wise cell demapper 611220.

[0283] Also, the first pair-wise frequency deinterleaver 61110 and the
first pair-wise cell demapper 611120 or the second pair-wise frequency
deinterleaver 611210 and the second pair-wise cell demapper 611220 can
operate independently and the same through a first route and a second
route respectively.

[0284] Also, the frame demapper illustrated in FIG. 21 can perform the
reverse process of the frame builder illustrated in FIG. 18.

[0285] A method of performing data by blocks included in the first frame
builder demapping block 611100 and the second frame builder demapping
block 611200 is as follows.

[0286] The first pair-wise frequency deinterleaver 611110 and the second
pair-wise frequency deinterleaver 611210 perform deinterleaving in data
in the frequency domain through the first and seoncd routes into cell
units in that case, the first pair-wise frequency deinterleaver 611110
and the second frequency deinterleaver 611210 pair up two consecutive
cells in deinterleaving units and perform frequency deinterleaving. The
deinterelaving process can be performed in a reverse direction of the
interleaving process in the transmitting unit. The
frequency-deinterleaved data will be transmitted in the original order.

[0287] The first pair-wise cell demapper 611120 and the second pair-wise
cell demapper 611220 can extract common PLP data, PLP data and
L1-signaling information in cell units from the de-interleaved data. The
extracted PLP data includes MISO PLP data for the MISO method and MIMO
PLP data for the MIMO method, and the extracted L1-signaling data
includes information necessary for the current and next frames. Also, if
the transmitter performs sub-slicing in the PLP data, the first and the
second pair-wise cell demappers 611120, 611220 can merge the sliced PLP
data and generate it in one stream.

[0288] Also, the first pair-wise cell demapper 611120 and the second
pair-wise cell demapper 611220 can pair up two consecutive cells.

[0289] Data transmitted through the first route is inputted to the BICM
decoder by the route from SRx--0 to SRxpost and data transmitted
through the second route is inputted to the BICM decoder by the route
from SRx--0+1 to SRxpost+1.

[0290] The frame demapper shown in FIG. 21 may be applied to the first and
second embodiments of the present invention. In accordance with the third
and fourth embodiments of the present invention, the frame demapper
includes a first frame demapping block 627100 performing data from a
first route and a second frame demapping block 627200 performing data
from a second route.

[0291] The first frame demapping block includes a first frequency
deinterleaver, a first cell demapper, a first combiner, a second combiner
and a third combiner, and the second frame demapping block includes a
second frequency deinterleaver and a second cell demapper.

[0292] Also, the first frequency deinterleaver and the first cell demapper
or the second frequency deinterleaver and the second cell demapper can
operate independently and the same through a first route and a second
route respectively.

[0293] The first frequency deinterleaver and the second frequency
deinterleaver perform deinterleaving in data in the frequency domain
through the first and seoncd routes into cell units.

[0294] The first and second cell demppers perform extracting common PLP
data, PLP data and L1-signaling data from the deinterleaved data by cell
units. The extracted PLP data includes the MISO decoded MISO PLP data and
MIMO decoded MIMO PLP data, and the extracted L1-signaling data includes
information necessary for the current and next frames. Also, if the
transmitter performs sub-slicing in the PLP data, the first sub-slice
processor 627120-1, 627220-1 of the first and the second cell demappers
627120, 627220 can merge the sliced PLP data and generate it in one
stream.

[0295] The first combiner can combine the MISO decoded MISO PLP data if it
does not combine the MISO PLP data in the MIMO/MISO decoder,

[0296] The second combiner and the third combiner can operate the same as
the first combiner but it deals with L1-pre and L1-post signaling data.

[0297] FIG. 22 shows a BICM encoder according to an embodiment of the
present invention.

[0298] The BICM encoder in FIG. 22 according to the first embodiment of
the present invention is an embodiment of the BICM encoder 107300 in FIG.
2.

[0299] The BICM decoder according to the first embodiment receives data
from the first route via SRx--0 to SRx_post by a frame demapper and
data from the second route via SRx--0+1 to SRx_post+1 and performs
BICM decoding.

[0300] Also, the BICM decoder according to the first embodiment
independently performs MISO/MIMO encoding in each of the data.

[0301] That is, the BICM decoder in FIG. 22 includes a first BICM decoding
block 612100 performing MISO PLP data from SRx_k and SRx_k+1, a second
BICM decoding block 612200 performing MIMO PLP data from SRx_m and
SRx_m+1, and a third BICM decoding block 612300 performing MISO encoding
in the L1-signaling information from SRx_pre, SRx_pre+1, SRx_post, and
SRx_post+1.

[0302] Also, the BICM decoder according to the first embodiment of the
present invention can perform the reverse process of the BICM encoder
according to the first embodiment of the present invention illustrated in
FIG. 16.

[0303] Data-performation method for each block is illustrated.

[0304] First, the first BICM decoding block 612100 includes a time
deinterleaver 612110-1, 612110-2, a cell deinterleaver 612120-1,
612120-2, a MISO decoder 612130, a constellation demapper 612140, a first
demultiplexer 612150, a bit deinterleaver 612160, and a FEC decoder
612170.

[0305] The time deinterleaver 612110-1, 612110-2 restores the MISO decoded
data into a time domain and the cell deinterleaver 612120-1, 612120-2
performs deinterleaving in the time-deinterleaved data into cell units.

[0307] First, if the channel estimation modules 610180, 610280 included in
the OFDM demodulator illustrated in FIG. 20 do not perform channel
equalizing, the MISO decoder 612130 applies the effect of the channel
detection regarding every transmissible reference point and computes an
LLR value. Therefore, it will have the same effect.

[0308] Second, the MISO decoder 612130 performs the following functions
based on the performance of the constellation mapper 604140. If the BICM
encoder of the broadcast signal transmitter rotates the constellation
mapper with a certain angle and delays the Q-phase element of the
constellation for a certain value, the MISO decoder 612130 delays the
1-phase element of the constellation for a certain value and computes a
2D-LLR value based on the rotation angle.

[0309] If the constellation mapper 604140 does not rotate constellation
and does not delay the Q-phase of constellation for a certain value, the
MSIO decoder 612130 can compute the 2-D LLR value based on the normal
QAM.

[0310] Third, the MISO decoder 612130 selects a decoding matrix to perform
the reverse process based on the encoding matrix used by the MISO encoder
604150.

[0311] Fourth, the MISO decoder 612130 can combine signals inputted from
two antennas. The signal combining method includes maximum ratio
combining, equal gain combining, and selective combining and obtains the
diversity effect by maximizing the SNR of the combined signals.

[0313] The constellation demapper 612140 can perform the following
functions based on the performance of the MISO decoder 612130.

[0314] First, if the MISO decoder 612130 does not transmit the LLR value
directly and only performs MISO decoding, the constellation demapper
612140 can compute the LLR value. In more detail, if the constellation
demapper 604140 in the BICM encoder performs constellation rotation or
Q-phase element delay, the constellation demapper 612140 delay the
I-phase LLR element and computes the LLR value. If the constellation
demapper 604140 does not perform the constellation rotation and Q-phase
element delay, the constellation demapper 612140 can compute the LLR
value based on the normal QAM.

[0315] The computing the LLR value includes computing 2-D LLR and
computing 1-D LLR. When computing the 1-D LLR, the complexity of the LLR
computation can be reduced by executing either one of a first or a second
route.

[0317] The bit-interleaver 612160 performs deinterleaving in the
bit-stream, FEC decoding in the deinterleaved data, and outputs MISO PLP
data by correcting errors in the transmitting channels.

[0318] The second BICM decoding block 612200 includes a first time
deinterleaver 612210-0 and a second time deinterleaver 612210-1, a first
cell deinterleaver 612220-0 and a second cell deinterleaver 612220-1, a
MIMO decoder 612230, a first constellation demapper 612240-0 and a second
constellation demapper 612240-1, a second multiplexer 612250, a bit
interleaver 612260 and a FEC decoder 612270.

[0319] The first time deinterleaver 612210-0 and the second time
deinterleaver 612210-1 perform deinterleaving in the MIMO decoded data
into cell units. In that case, the first cell deinterleaver 612220-0 and
the second deinterleaver 612220-1 performs cell deinterleaving in only a
half of the cell data in one FEC block. As a result, cell deinterleaving
by the first and second cell deinterleaver 612220-0, 612220-1 has the
same effect as deinterleaving by a cell deinterleaver using one FEC
block.

[0320] The MIMO decoder 612230 performs in MIMO PLP data from SRxm and
SRxm+1. The MIMO decoder 612210 can perform the four functions of the
MISO decoder 612110 except for the fourth function in which the signals
are to be combined. Then, the MIMO decoder 612230 performs decoding by
using MIMO encoding matrix of the first and sixth embodiment.

[0321] The first constellation demapper 612240-0, the second constellation
demapper 612240-1, the second multiplexer 612250, bitinterleaver 612260
and FEC decoder 612270 operates the same as those according to the first
BICM decoding block 612100.

[0322] The third BICM decoding block 612300 includes a first decoding
block 612400 performing L1-pre signaling data and a second decoding block
612500 performing L1-post signaling data. The first decoding block 612400
includes a time deinterleaver 612410-1, 612410-2, a cell deinterleaver
612420-1, 612420-2, a MISO decoder 612430, a constellation demapper
612440, and a FEC decoder 612450, and the second decoding block 612500
includes a time deinterleaver 612510-1, 612510-2, a cell deinterleaver
612520-1, 612520-2, a MISO decoder 612530, a constellation demapper
612540, a multiplexer 612550, a bit deinterleaver 612560, and a FEC
decoder 612570.

[0323] As the first decoding block 612400 and the second decoding block
612500 have the same functions, the description of the first BICM
decoding block 612100 is omitted.

[0324] As a result, the first BICM decoding block 612100 outputs the BICM
decoded MISO PLP data to an output processor and the second BICM decoding
block 612200 transmits the BICM decoded MIMO PLP data to the output
processor.

[0325] The first decoding block 612400 in the third BICM decoding block
612300 performs MSIO decoding in L1-pre signaling data and transmits the
data. Also, the second decoding block 612500 in the third BCIM decoding
block 612300 performs MISO decoding in L1-post signaling data and
transmits one L1-post signaling information.

[0326] FIG. 23 shows a BICM decoder according to another embodiment of the
present invention.

[0327] The BICM decoder in FIG. 23 according to the second embodiment of
the present invention is an embodiment of the BICM decoder 107300 in FIG.
2.

[0328] The BICM decoder according to the second embodiment receives data
transmitted from a first route to a route of from SRxO to SRx_post and
data transmitted from a second route to a route of from SRx--0+1 to
SRx_post+1, and performs BICM decoding. Also, the BICM decoder according
to the second embodiment can independently apply the MISO/MIMO process.

[0329] That is, the BICM decoder in FIG. 23 includes a first BICM decoding
block 615100 performing MISO encoding in MSIO PLP data from SRx_k and
SRx_k+1, a second BICM decoding block 615200 performing in MIMO PLP data
from SRx_post and SRx_post+1, and a third BICM decoding block 615300
performing MISO encoding in L1-signaling data from SRx_pre, SRx_pre+1,
SRx_post, and SRx_m+1.

[0330] Also, the third BICM decoding block 615300 includes a first
decoding block 615400 performing the L1-pre signaling data and a second
decoding block 615500 performing L1-post signaling data.

[0331] Also, the BICM decoder according to the second embodiment can
perform the reverse process of the BICM encoder according to the second
embodiment illustrated in FIG. 17.

[0332] The decoding blocks according to the second embodiment in FIG. 23
operate the same as the decoding blocks according to the first embodiment
in FIG. 22. Therefore, further description is omitted. However, the only
difference is that in the BICM decoder the MISO decoder 615110, 615410,
615510 and the MIMO decoder 615310 are located in front of the time
deinterleaver deinterleaver 615120, 615220-1, 615220-2, 615420, 615520.

[0333] As above described, the PLP data and the signaling information are
performed into symbol units after the constellation mapping. In addition,
the broadcast signal receiver may perform BICM decoding on data received
in reverse processes to those of the BICM encoding blocks according to
the first embodiment or the second embodiment. In this case, a MISO
decoder, a MIMO decoder, a time deinterleaver, and a cell deinterleaver
of the broadcast signal receiver may perform the received data in symbol
units. However, the BICM decoder of the broadcast signal receiver may
first perform MISO decoding or MIMO decoding for each data, and thus,
each data is output in bit units. Then, the BICM decoder of the broadcast
signal receiver may perform time deinterleaving and cell deinterleaving
processes, but requires information regarding a symbol unit of data
output in bit units. Thus, the broadcast signal receiver may store
information regarding symbol mapping of input bits required for the
deinterleaving processes.

[0334] As not shown in drawings, the BICM decoder according to the third
embodiment includes a first BICM decoding block processing the MISO
decoded MISO PLP data transmitted through one path, a second BICM
decoding block processing the MIMO decoded MIMO PLP data transmitted
through two paths, and a third BICM decoding block processing the MISO
encoded L1-signaling data transmitted through two paths. Also, the third
BICM decoding block includes a first decoding block processing L1-pre
signaling data and a second decoding block processing L1-post signaling
data.

[0335] Also, as the BICM decoder according to the third embodiment
operates the same as the BICM encoding blocks according to the first
embodiment in FIG. 22. However, the only difference is that the BICM
decoding blocks according to the third embodiment do not include
MISO/MIMO decoders.

[0336] Also, the BICM decoder according to the fourth embodiment of the
present invention includes a first BICM decoding block processing MISO
PLP data transmitted through one path, a second BICM decoding block
processing MIMO PLP data transmitted through two paths, and a third BICM
decoding block processing MISO decoded L1-signaling data transmitted
through two paths.

[0337] Also, the third BICM decoding block includes a first decoding block
processing L1-signaling data and a second decoding block processing
L1-post signaling data.

[0338] As the first BICM decoding block according to the fourth embodiment
operates the same as the BICM decoding blocks illustrated in FIG. 22.

[0339] But, the only difference is that the second BICM decoding block
includes the MIMO decoder as opposed to the third embodioment of the
present invention. In that case, the transmitting character of MIMO PLP
data from a first and a second route may or may not be the same. Also, if
the modulation orders of the two MIMO PLP data are the same, a second
constellation mapper, a second cell interleaver and a second time
interleaver may not be used. Thus, two of the MIMO PLP data will be
merged into one input in the first time deinterleaver, the first cell
deinterleaver, the first constellation demapper, and then will be
inputted to the second multiplexer. In addition, the MIMO decoder may be
positioned in front of the time deinterleavers as in the first embodiment
or may be positioned in front of the constellation demappers as in the
second embodiment.

[0340]FIG. 24 and FIG. 25 show an embodiment of an output processor
included broadcast signal receiver according to an embodiment of the
present invention. The following is a specific description of the output
processor.

[0341]FIG. 24 shows an output processor of the broadcast signal receiver
according to an embodiment.

[0342] The output processor in FIG. 24 is an embodiment of the output
processor 107400 in FIG. 2.

[0343] The output processor in FIG. 24 as opposed to an input processor
performing single PLP in FIG. 13 performs the reverse process of it and
includes a BB discrambler 616100, a padding remove module 616200, a CRC-8
decoder 616300 and a BB frame processor 616400. The output processor
performs the reverse process of the input processor illustrated in FIG.
13 by receiving bit stream from the BICM decoder.

[0344] The BB descrambler 616100 receives bit stream, performs XOR
algorithm with the same bit-string as PRBS processed by the BB scrambler
and outputs it. The padding remove module 616200 removes, if necessary,
padding bits inserted in the padding insertion module. The CRC-8 decoder
616300 performs CRC decoding in the bit-stream and the BB frame processor
616400 decodes information in the BB frame header and restores TS or GS
by using the decoded information.

[0345]FIG. 25 shows another embodiment of an output processor of the
present invention.

[0346] The output processor in FIG. 25 as opposed to the input processor
in FIG. 14 and FIG. 15 performing a plurality of PLP performs the reverse
process of it. The output processor includes a plurality of blocks for a
plurality of PLP. The blocks are as follows. The output processor
includes a BB descrambler 617100, 617400-1, 617400-2 and a padding
removal module 617120, a CRC-8 decoder 617130, a BB frame processor
617140, a De jitter buffer 617150, a null packet insertion module 617160,
a TS clock regeneration module 617170, an in-band signaling decoder
617180, a TS recombination module 617300 and a L1 signaling decoder
617410. The same blocks as in FIG. 24 are omitted.

[0347] Processing for a plurality of PLP can be shown as decoding PLP data
regarding common PLP or decoding service components like scalable video
service or a plurality of services at once. The BB descrambler 617110,
the padding removal module 617120, the CRC-8 decoder 617130 and the BB
frame processor 617140 operate the same as those in FIG. 40.

[0348] The De jitter buffer 617150 compensates a temporarily inserted
delay for the synchronization of a plurality of PLP based on Time To
Output (TTO) parameters. The null packet insertion module 617160 restores
the deleted null packet based on the Deleted Null Packet (DNP)
information. The TS clock regeneration module restores the detailed time
synchronization of the outputted packet based on Input Stream Time
Reference information. The TS recombination module 617300 receives the
restored common PLP and related PLP data and transmit the original TS, IP
or GS. The TTO parameters, DNP information, and ICSR information are
obtained by the BB frame processor and it can transmit the data to each
block or a system controller.

[0350] As for L1 signaling information, the BB descramblers 617400-1,
617400-2 performs descrambling in the corresponding L1 pre signaling
information data and L1-post signaling information, and the L1 signaling
decoder 6174100 decodes the descrambled data and restores the L1
signaling information. The restored L1-signlaing information includes
L1-pre signaling information and L1-post signaling information. It will
also be transmitted to the system controller and provides parameters for
BICM decoding, frame demapping, and OFDM demodulating. The L1 signaling
information can be inputted as one BB descrambler and will be
descrambled.

[0351] FIG. 26 shows a frame structure according to one embodiment of the
present invention.

[0352] As described above, the frame builder 101400 of FIG. 1 may generate
a frame upon receiving output data from the BICM encoder 101300. In this
case, the output signaling information or PLP data may be processed by at
least one of SISO, SIMO, MISO, and MIMO. However, SIxO-processed data and
MIxO-processed data may have different pilot densities such that it is
impossible for the SIxO-processed data and the MIxO-processed data to be
simultaneously contained in the same frame. Therefore, according to one
embodiment of the present invention, a symbol P1 and two subframes are
contained in a single frame. In this case, two subframes may transmit
SIxO-processed data and MIxO-processed data, respectively. One frame may
also include the symbol P1 and only one subframe. In this case,
SIxO-processed data and MIxO-processed data may be transmitted on a frame
basis. The above-mentioned data transmission may be changed according to
a designer's intention.

[0353] FIG. 26 shows an exemplary case in which P1 symbol 2600, a first
subframe 2610, and a second subframe 2620 are contained in a single
frame. A detailed description of FIG. 26 is as follows.

[0354] P1 symbol 2600 may be located prior to the frame, and may transmit
information regarding a structure of a subframe contained in the
corresponding frame. That is, the receiver may recognize whether the
corresponding frame includes only one subframe or two different subframes
through information included in the P1 symbol. In addition, the P1 symbol
may perform SISO or SIMO processing for implementing data reception
through even one antenna.

[0355] The first subframe 2610 may transmit SISO or SIMO processed data to
enhance robustness. Therefore, the first subframe 2610 may include a PLP
for transmitting SISO- or SIMO-processed L1 signaling information and a
data PLP for transmitting a service or service component. In this case,
PLP for transmitting L1 signaling information may include not only
information regarding a first subframe but also information regarding a
second subframe.

[0356] The second subframe 2610 may transmit MISO- or MIMO-processed data
so as to improve transmission efficiency through a multiplexing gain.
Therefore, the second subframe 2620 may include a signaling PLP for
transmitting PLP information and a data PLP for transmitting the service
or the service component. In this case, Alamouti coding such as
SFBC/STBC, or TxAS (transmitter antenna switching), etc. may be used as
the MIMO processing method.

[0357] In order to increase the efficiency of data transmitted through the
second subframe 2620, data can be processed with a high code rate and a
high constellation order, and may also be processed with a MIMO scheme, a
Spatial Multiplexing (SM) scheme, a Golden Code (GC) scheme, etc.

[0358] As described above, since data transmitted from the first subframe
2610 and data transmitted from the second subframe 2620 have different
characteristics, an FFT size, a GI size, and a pilot pattern of each
subframe may be decided in different ways. In more detail, the FFT size,
the GI size, and the pilot pattern of the first subframe 2610 may be
decided in response to mobility or indoor reception of the receiver; and
the FFT size, the GI size, and the pilot pattern of the second subframe
2620 may be decided to obtain a high transfer rate.

[0359] If two subframes use different pilot patterns, channel equalization
performance of the receiver may be deteriorated. Therefore, assuming that
two subframes according to the present invention use different pilot
patterns, an edge pilot may be inserted into an OFDM symbol located at
the front end or the rear end of each subframe according to one
embodiment.

[0360] Therefore, the receiver may obtain information regarding a subframe
contained in the corresponding frame by decoding the P1 symbol 2600. A
decoding process for each subframe is performed such that the service or
the service component can be obtained from a necessary PLP.

[0361] FIG. 27 shows a frame structure according to another embodiment of
the present invention.

[0362] Referring to FIG. 27, the frame structure may be classified into
Type 1 subframe and Type 2 subframe according to a sub-slice (or burst)
configured to transmit a PLP. That is, assuming that the PLP contained in
the subframe is transmitted through one sub-slice, the corresponding
subframe may be referred to as Type 1 subframe. If the PLP contained in
the subframe is transmitted through a plurality of subslices, the
corresponding subframe may be referred to as Type 2 subframe.

[0363] In case of Type 1 subframe, since the service or the service
component is transmitted by one subslice, the receiver can recover a
desired service upon receiving the corresponding subslice. Therefore, the
receiver can obtain the power saving effect. In addition, in case of Type
2 subframe, the corresponding service or the service component is
transmitted through a plurality of subslices in a time domain of the
corresponding subframe, the receiver may obtain a time-interleaving gain.

[0364] Even in the case of Type 1 subframe, if interleaving between
subframes (i.e., inter-frame interleaving) is performed, it is possible
to obtain a time interleaving gain whereas latency increases, In case of
Type 2 subframe, if interleaving belonging to the corresponding subframe
(i.e., intra-frame interleaving) is performed, it is possible to obtain a
diversity gain and a short latency.

[0365] FIG. 27A shows an interleaved frame structure on the condition that
the first subframe is any one of Type 1 subframe and the second subframe
is Type 2 subframe.

[0366] Referring to FIG. 27A, inter-frame interleaving may be carried out
in either PLP 1 contained in a first subframe of the first frame and
another PLP 1 contained in a first subframe of the second frame, such
that it is possible to obtain an interleaving gain of the PLP1. As shown
in FIG. 27B, intra-frame interleaving may be carried out in either PLP2
contained in a second subframe of the first frame and another PLP2
contained in a second subframe of the second frame, such that it is
possible to obtain an interleaving gain of the PLP2.

[0367] FIG. 27B shows an interleaved frame structure on the condition that
the first subframe is any one of Type 2 subframe and the second subframe
is Type 1 subframe.

[0368] Referring to FIG. 27B, the first and second subframes contained in
the first and second subframes may perform intra-frame interleaving
within each subframe according to one embodiment. In this case, the
receiver may minimize power consumption of a PLP2 transmitted to the
second subframe, resulting in reduction of latency. Specifically, data
transmitted through the second subframe is MIMO-processed to have high
efficiency, such that a time required for data transmission is gradually
shorter than that of SISO or MISO. Therefore, a power-saving gain of the
receiver may be more greatly increased.

[0369] As described above, data transmitted through a first subframe and a
second subframe may have different physical characteristics. Therefore,
in order to allow the receiver to decode data transmitted through each
subframe, signaling information for each subframe is needed. L1 signaling
information of FIG. 3 may include signaling information of each subframe
according to one embodiment of the present invention.

[0370] In more detail, a configuration block contained in the above L1-pre
signaling information or L1-post signaling information may include
specific information indicating whether a local service is transmitted
and associated physical information. Therefore, the receiver determines
whether or not a local service is transmitted by decoding L1-pre
signaling information or L1-post signaling information. If the local
service is transmitted, the receiver may confirm physical characteristics
of the local service.

[0371] As described above, assuming that one frame includes a first
subframe and a second subframe, a configurable block or dynamic block
contained in L1-pre signaling information and L1-post signaling
information may include parameters for each subframe. In more detail,
configurable parameters of each subframe may include a MIMO_TYPE field,
an FFT_SIZE field, a GUARD_INERVAL field, a PILO_PATTERN field, a
NUM_MIMO_SYMBOL field, etc. Detailed description thereof is as follows.

[0372] MIMO_TYPE field is a field indicating a MIMO scheme for processing
data transmitted through a subframe. MIMO scheme may be SIxO, MISO, MIMO,
etc.

[0373] FFT_SIZE field may indicate an FFT size used in the subframe.

[0374] GUARD_INERVAL field may indicate the size of a guard interval of a
current subframe.

[0375] PILOT_PATTERN field is a field indicating a pilot insertion pattern
of a current subframe.

[0376] NUM_MIMO_SYMBOL field is a field indicating the number of OFDM
symbols of MIMO-processed data contained in the subframe. The number of
OFDM symbols of SIxo- or MISO-processed data is obtained when the number
of OFDM symbols of MIMO-processed data is subtracted from the number of
OFDM symbols constructing the total frame.

[0377] Therefore, the receiver decodes a configurable block or a dynamic
block contained in the L1-pre signaling information and L1-post signaling
information so as to obtain parameters of each subframe, such that it can
obtain a subframe structure belonging to one frame.

[0378] As shown in FIG. 4, one super-frame may include a plurality of
frames. One superframe may include a T2 frame for transmitting data of a
legacy broadcast system (or T2 broadcast system) and an NGH frame for
transmitting data of the NGH broadcast system. Therefore, one superframe
may include a plurality of T2 (or legacy frame) frames and NGH frames.

[0379] FIG. 28 shows a superframe structure according to one embodiment of
the present invention.

[0380] Referring to FIG. 28A, individual NGH frames contained in one
superframe may include the same first and second subframes.

[0381] In this case, one NGH frame 2800 may include a first subframe 2801
and a second subframe 2802. The first subframe 2801 shown in FIG. 28A may
include a plurality of parameters such as SISO, a size of 2K FFT, a guard
interval of 1/4 GI, a pilot pattern of PP1, etc. The second subframe 2802
may include a plurality of parameters such as MIMO, a size of 8K FFT, a
guard interval of 1/8 GI, a pilot pattern of PP2, etc. In this case,
parameters of each subframe may be transmitted through a configurable
block of L1-pre signaling information or L1-post signaling information as
described above. In addition, the first subframe and the second subframe
contained in each NGH frame have the same physical parameters, and each
subframe may have a predetermined length.

[0382] FIG. 28B shows one embodiment in which individual NGH frame
contained in one superframe include different first and second subframes.

[0383] In this case, the first subframe and the second subframe contained
in each NGH frame may have different physical parameters.

[0384] Referring to FIG. 28B, a first subframe 2811 contained in the first
NGH frame 2810 may have a plurality of parameters such as SISO, a size of
2K FFT, a guard interval of 1/4 GI, a pilot pattern of PP1, etc. A second
subframe 2812 may have a plurality of paramters such as MIMO, a size of
8K FFT, a guard interval of 1/8 GI, a pilot pattern of PP4, etc. In
addition, a first subframe 2811-1 contained in the second NGH frame
2810-1 may have a plurality of parameters such as SISO, a size of 4K FFT,
a guard interval of 1/8 GI, a pilot pattern of PP2, etc. A second
subframe 2812-1 may have a plurality of parameters such as MIMO, a size
of 16K FFT, a guard interval of 1/8 GI, a pilot pattern of PP5, etc. In
addition, a first subframe 2811-2 contained in a third NGH frame 2810-2
may have a plurality of parameters such as MISO, a size of 8K FFT, a
guard interval of 1/16 GI, a pilot pattern of PP3, etc. A second subframe
281202 may have a plurality of parameters a plurality of parameters such
as MIMO, a size of 8K FFT, a guard interval of 1/16 GI, a pilot pattern
of PP3, etc.

[0385] In this case, parameters of individual subframes are different
according to respective subframes, such that the parameters may be
transmitted through a dynamic block of L1-post signaling information.
However, the same length of NGH frame should be maintained within the
superframe. The first subframe and the second subframe contained in each
NGH frame maintain different ration of length, such that the same-length
NGH frame can be configured.

[0386] In accordance with the designer intention, a first subframe and a
second subframe contained in some NGH frames of the superframe may have
the same parameters as shown in FIG. 28A. In addition, the first subframe
and the second subframe contained in the remaining NGH frame may have
different parameters as shown in FIG. 28B.

[0387] In this case, parameters equally applied to individual subframes of
the superframe can be transmitted through the configurable block of the
L1-pre signaling information or L1-post signaling information, and
parameters differently applied to individual subframes may be transmitted
through a dynamic block of L1-post signaling information.

[0388]FIG. 29 is a flowchart illustrating a method for transmitting a
broadcast signal according to one embodiment of the present invention.

[0389] As shown in FIG. 1, the BICM encoder 101300 according to one
embodiment may encode PLP (Physical_Layer_Pipe) data and signaling
information including a base layer and an enhancement layer of a
broadcast service using at least one of SISO, MISO, and MIMO in step
S2900.

[0390] In this case, the broadcast signal transmitter according to one
embodiment of the present invention may independently perform MISO
processing and MIMO processing for each input PLP data during the BICM
encoding process according to a first embodiment. Alternatively,
according to a second embodiment, the broadcast signal transmitter may
independently perform MISO processing and MIMO processing for each input
PLP data during the BICM encoding process. In addition, MISO processing
and MIMO processing may be performed for mapped PLP data within a frame
during the OFDM generation process according to a third embodiment. In
accordance with a fourth embodiment, independent MIMO processing may be
applied to MIMO PLP data to be MIMO processed from among PLP data to be
used as input data in the BICM encoding process. The OFDM generator may
perform MISO processing for not only MISO PLP data requisite for MISO
processing but also L1-signaling information.

[0391] In more detail, as shown in FIGS. 16 and 17, the BICM encoder of
the broadcast signal transmitter according to a first embodiment may
perform MISO encoding or MIMO encoding for input PLP data after
completion of constellation mapping, cell interleaving, and time
interleaving. The BICM encoder of the broadcast signal transmitter
according to the second embodiment may perform MISO encoding or MIMO
encoding for each input PLP data after completion of constellation
mapping, and may perform cell interleaving and time interleaving.

[0392] Thereafter, the frame builder 101400 according to one embodiment
may generate a transmission frame including a preamble and PLP data
including the encoded signaling information in step S2910. If signaling
information and PLP data are processed according to the first and second
embodiments, the frame builder according to one embodiment combines
symbol-based PLP data and symbol-based L1-signaling data received through
each path in units of two cells, such that it may map a pair of two cells
to an OFDM symbol carrier.

[0393] In addition, assuming that signaling information and PLP data are
processed according to the third and fourth embodiments, the frame
builder according to one embodiment may prevent MISO PLP data and MIMO
PLP data from being mapped into the same OFDM symbol.

[0394] In addition, the frame builder according to one embodiment may
include a first subframe and a second subframe in one frame as shown in
FIGS. 26 to 28. In this case, SIxO-processed data may be transmitted
through the first subframe, and MIxO-processed data may be transmitted
through the second subframe. However, such data transmission may be
changed according to the designer intention.

[0395] In addition, individual subframes may be assigned the same or
different parameters of PLP data contained in the first and second
subframes ac cording to the designer intention.

[0396] Thereafter, the OFDM generator 101500 according to one embodiment
may perform OFDM modulation of a broadcast signal including the
transmission frame, and transmit the OFDM-modulated broadcast signal in
step S2920. In accordance with a third embodiment of FIG. 20, the OFDM
generator may include a MISO/MIMO encoder. In accordance with a fourth
embodiment of the present invention, the OFDM generator may include the
MISO encoder.

[0397]FIG. 30 is a flowchart illustrating a method for receiving a
broadcast signal according to one embodiment of the present invention.

[0398] The OFDM demodulator 107100 according to one embodiment receives a
broadcast signal including a transmission frame configured to transmit a
broadcast service so that it may OFDM-demodulate the broadcast signal in
step S3000. In accordance with the third embodiment of the present
invention, the OFDM demodulator may include the MISO/MIMO decoder. In
accordance with the fourth embodiment of the present invention, the OFDM
demodulator may include the MISO decoder.

[0399] Thereafter, the frame parser 107200 according to one embodiment may
parse the transmission frame contained in the OFDM-demodulated broadcast
signal in step S3010. In this case, the transmission frame may include a
preamble and PLP data, and the preamble may include signaling
information.

[0400] Referring to FIG. 21, according to the first and second embodiments
of the present invention, the frame parser combines and extracts two
contiguous cells mapped to each frame. In addition, as shown in FIGS. 26
to 28, one frame may include a first subframe and a second subframe. In
this case, the broadcast receiver may receive SIxO-processed data through
the first subframe, and receive MIxO-processed data through the second
subframe according to the designer intention.

[0401] In addition, individual subframes may be assigned the same or
different parameters of PLP data contained in the first and second
subframes. Assuming that the same parameters are assigned to respective
subframes, the receiver may receive parameters through the configurable
block of L1-pre signaling information or L1-post signaling information.
In addition, assuming that different parameters are assigned to
respective subframes, the receiver may receive parameters through a
dynamic block of L1-post signaling information.

[0402] Thereafter, the BICM decoder 107300 according to one embodiment may
decode signaling information and PLP data using at least one of SISO,
MISO and MIMO in step S3020. As shown in FIGS. 22 and 23, the BICM
decoder according to the first and second embodiments may independently
apply the MISO scheme to input data received from each path, may
independently apply the MIMO scheme to the input data, and may also
independently apply the MISO scheme to the signaling information. The
BICM decoder according to the third embodiment may not include the MISO
decoder and the MIMO decoder, and the BICM decoder according to the
fourth embodiment may include only the MIMO decoder.

MODE FOR INVENTION

[0403] Various embodiments have been described in the best mode for
carrying out the invention.

INDUSTRIAL APPLICABILITY

[0404] As described above, embodiments of the present invention can be
totally or partially applied to the digital broadcast system.